Merge pull request #1598 from ferd/unicode-bonanza

Unicode support in all the places

47 files changed, 433 insertions, 413 deletions

diff --git a/src/rebar3.erl b/src/rebar3.erl
index 1e1d0b0..eec8968 100644
--- a/src/rebar3.erl
+++ b/src/rebar3.erl
@@ -183,11 +183,11 @@ init_config() ->
     GlobalConfigFile = rebar_dir:global_config(),
     State = case filelib:is_regular(GlobalConfigFile) of
                 true ->
-                    ?DEBUG("Load global config file ~s", [GlobalConfigFile]),
+                    ?DEBUG("Load global config file ~ts", [GlobalConfigFile]),
                     try state_from_global_config(Config1, GlobalConfigFile)
                     catch
                         _:_ ->
-                            ?WARN("Global config ~s exists but can not be read. Ignoring global config values.", [GlobalConfigFile]),
+                            ?WARN("Global config ~ts exists but can not be read. Ignoring global config values.", [GlobalConfigFile]),
                             rebar_state:new(Config1)
                     end;
                 false ->
@@ -270,7 +270,7 @@ log_level() ->
 -spec version() -> ok.
 version() ->
     {ok, Vsn} = application:get_key(rebar, vsn),
-    ?CONSOLE("rebar ~s on Erlang/OTP ~s Erts ~s",
+    ?CONSOLE("rebar ~ts on Erlang/OTP ~ts Erts ~ts",
              [Vsn, erlang:system_info(otp_release), erlang:system_info(version)]).
 
 %% @private set global flag based on getopt option boolean value
@@ -311,11 +311,11 @@ handle_error({error, {Module, Reason}}) ->
             ?DEBUG("Uncaught error: ~p ~p", [Module, Reason]),
             ?INFO("When submitting a bug report, please include the output of `rebar3 report \"your command\"`", []);
         _ ->
-            ?ERROR("~s", [Module:format_error(Reason)])
+            ?ERROR("~ts", [Module:format_error(Reason)])
     end,
     erlang:halt(1);
 handle_error({error, Error}) when is_list(Error) ->
-    ?ERROR("~s", [Error]),
+    ?ERROR("~ts", [Error]),
     erlang:halt(1);
 handle_error(Error) ->
     %% Nothing should percolate up from rebar_core;
diff --git a/src/rebar_agent.erl b/src/rebar_agent.erl
index 627ed96..b5dcfcf 100644
--- a/src/rebar_agent.erl
+++ b/src/rebar_agent.erl
@@ -157,7 +157,7 @@ refresh_paths(RState) ->
                 {ok, Mods} ->
                     case {length(Mods), length(Mods -- Blacklist)} of
                         {X,X} ->
-                            ?DEBUG("reloading ~p from ~s", [Modules, Path]),
+                            ?DEBUG("reloading ~p from ~ts", [Modules, Path]),
                             code:replace_path(App, Path),
                             reload_modules(Modules);
                         {_,_} ->
diff --git a/src/rebar_app_discover.erl b/src/rebar_app_discover.erl
index de72c09..cdd183c 100644
--- a/src/rebar_app_discover.erl
+++ b/src/rebar_app_discover.erl
@@ -60,7 +60,7 @@ do(State, LibDirs) ->
                                 rebar_state:project_apps(StateAcc1
                                                         ,rebar_app_info:deps(AppInfo2, ProjectDeps1));
                             false ->
-                                ?INFO("Ignoring ~s", [Name]),
+                                ?INFO("Ignoring ~ts", [Name]),
                                 StateAcc
                         end
                 end, State1, SortedApps).
@@ -233,7 +233,7 @@ app_dirs(LibDir, SrcDirs) ->
     EbinPath = filename:join([LibDir, "ebin", "*.app"]),
 
     lists:usort(lists:foldl(fun(Path, Acc) ->
-                                Files = filelib:wildcard(ec_cnv:to_list(Path)),
+                                Files = filelib:wildcard(rebar_utils:to_list(Path)),
                                 [{app_dir(File), SrcDirs}
                                  || File <- Files] ++ Acc
                             end, [], [EbinPath | Paths])).
@@ -386,7 +386,7 @@ try_handle_app_file(AppInfo0, [File], AppDir, AppSrcFile, _, Validate) ->
             end
     catch
         throw:{error, {Module, Reason}} ->
-            ?DEBUG("Falling back to app.src file because .app failed: ~s", [Module:format_error(Reason)]),
+            ?DEBUG("Falling back to app.src file because .app failed: ~ts", [Module:format_error(Reason)]),
             try_handle_app_src_file(AppInfo0, File, AppDir, AppSrcFile, Validate)
     end;
 try_handle_app_file(_AppInfo, Other, _AppDir, _AppSrcFile, _, _Validate) ->
diff --git a/src/rebar_app_info.erl b/src/rebar_app_info.erl
index 62ec6dd..050ccc1 100644
--- a/src/rebar_app_info.erl
+++ b/src/rebar_app_info.erl
@@ -107,43 +107,43 @@ new() ->
 -spec new(atom() | binary() | string()) ->
                  {ok, t()}.
 new(AppName) ->
-    {ok, #app_info_t{name=ec_cnv:to_binary(AppName)}}.
+    {ok, #app_info_t{name=rebar_utils:to_binary(AppName)}}.
 
 %% @doc Build a new app info value with only the name and version set.
 -spec new(atom() | binary() | string(), binary() | string()) ->
                  {ok, t()}.
 new(AppName, Vsn) ->
-    {ok, #app_info_t{name=ec_cnv:to_binary(AppName),
+    {ok, #app_info_t{name=rebar_utils:to_binary(AppName),
                      original_vsn=Vsn}}.
 
 %% @doc build a complete version of the app info with all fields set.
 -spec new(atom() | binary() | string(), binary() | string(), file:name()) ->
                  {ok, t()}.
 new(AppName, Vsn, Dir) ->
-    {ok, #app_info_t{name=ec_cnv:to_binary(AppName),
+    {ok, #app_info_t{name=rebar_utils:to_binary(AppName),
                      original_vsn=Vsn,
-                     dir=ec_cnv:to_list(Dir),
-                     out_dir=ec_cnv:to_list(Dir)}}.
+                     dir=rebar_utils:to_list(Dir),
+                     out_dir=rebar_utils:to_list(Dir)}}.
 
 %% @doc build a complete version of the app info with all fields set.
 -spec new(atom() | binary() | string(), binary() | string(), file:name(), list()) ->
                  {ok, t()}.
 new(AppName, Vsn, Dir, Deps) ->
-    {ok, #app_info_t{name=ec_cnv:to_binary(AppName),
+    {ok, #app_info_t{name=rebar_utils:to_binary(AppName),
                      original_vsn=Vsn,
-                     dir=ec_cnv:to_list(Dir),
-                     out_dir=ec_cnv:to_list(Dir),
+                     dir=rebar_utils:to_list(Dir),
+                     out_dir=rebar_utils:to_list(Dir),
                      deps=Deps}}.
 
 %% @doc build a complete version of the app info with all fields set.
 -spec new(atom() | binary(), atom() | binary() | string(), binary() | string(), file:name(), list()) ->
                  {ok, t()}.
 new(Parent, AppName, Vsn, Dir, Deps) ->
-    {ok, #app_info_t{name=ec_cnv:to_binary(AppName),
+    {ok, #app_info_t{name=rebar_utils:to_binary(AppName),
                      parent=Parent,
                      original_vsn=Vsn,
-                     dir=ec_cnv:to_list(Dir),
-                     out_dir=ec_cnv:to_list(Dir),
+                     dir=rebar_utils:to_list(Dir),
+                     out_dir=rebar_utils:to_list(Dir),
                      deps=Deps}}.
 
 %% @doc update the opts based on the contents of a config
@@ -199,7 +199,7 @@ name(#app_info_t{name=Name}) ->
 %% @doc set the name of the app.
 -spec name(t(), atom() | binary() | string()) -> t().
 name(AppInfo=#app_info_t{}, AppName) ->
-    AppInfo#app_info_t{name=ec_cnv:to_binary(AppName)}.
+    AppInfo#app_info_t{name=rebar_utils:to_binary(AppName)}.
 
 %% @doc get the dictionary of options for the app.
 -spec opts(t()) -> rebar_dict().
@@ -249,14 +249,14 @@ set(AppInfo=#app_info_t{opts=Opts}, Key, Value) ->
 %% @doc finds the .app.src file for an app, if any.
 -spec app_file_src(t()) -> file:filename_all() | undefined.
 app_file_src(#app_info_t{app_file_src=undefined, dir=Dir, name=Name, opts=Opts}) ->
-    CandidatePaths = [filename:join([ec_cnv:to_list(Dir), Src, ec_cnv:to_list(Name)++".app.src"])
+    CandidatePaths = [filename:join([rebar_utils:to_list(Dir), Src, rebar_utils:to_list(Name)++".app.src"])
                       || Src <- rebar_opts:get(Opts, src_dirs, ["src"])],
     case lists:dropwhile(fun(Path) -> not filelib:is_file(Path) end, CandidatePaths) of
         [] -> undefined;
         [AppFileSrc|_] -> AppFileSrc
     end;
 app_file_src(#app_info_t{app_file_src=AppFileSrc}) ->
-    ec_cnv:to_list(AppFileSrc).
+    rebar_utils:to_list(AppFileSrc).
 
 %% @doc sets the .app.src file for an app. An app without such a file
 %% can explicitly be set with `undefined'.
@@ -264,12 +264,12 @@ app_file_src(#app_info_t{app_file_src=AppFileSrc}) ->
 app_file_src(AppInfo=#app_info_t{}, undefined) ->
     AppInfo#app_info_t{app_file_src=undefined};
 app_file_src(AppInfo=#app_info_t{}, AppFileSrc) ->
-    AppInfo#app_info_t{app_file_src=ec_cnv:to_list(AppFileSrc)}.
+    AppInfo#app_info_t{app_file_src=rebar_utils:to_list(AppFileSrc)}.
 
 %% @doc finds the .app.src.script file for an app, if any.
 -spec app_file_src_script(t()) -> file:filename_all() | undefined.
 app_file_src_script(#app_info_t{app_file_src_script=undefined, dir=Dir, name=Name}) ->
-    AppFileSrcScript = filename:join([ec_cnv:to_list(Dir), "src", ec_cnv:to_list(Name)++".app.src.script"]),
+    AppFileSrcScript = filename:join([rebar_utils:to_list(Dir), "src", rebar_utils:to_list(Name)++".app.src.script"]),
     case filelib:is_file(AppFileSrcScript) of
         true ->
             AppFileSrcScript;
@@ -277,7 +277,7 @@ app_file_src_script(#app_info_t{app_file_src_script=undefined, dir=Dir, name=Nam
             undefined
     end;
 app_file_src_script(#app_info_t{app_file_src_script=AppFileSrcScript}) ->
-    ec_cnv:to_list(AppFileSrcScript).
+    rebar_utils:to_list(AppFileSrcScript).
 
 %% @doc sets the .app.src.script file for an app. An app without such a file
 %% can explicitly be set with `undefined'.
@@ -285,12 +285,12 @@ app_file_src_script(#app_info_t{app_file_src_script=AppFileSrcScript}) ->
 app_file_src_script(AppInfo=#app_info_t{}, undefined) ->
     AppInfo#app_info_t{app_file_src_script=undefined};
 app_file_src_script(AppInfo=#app_info_t{}, AppFileSrcScript) ->
-    AppInfo#app_info_t{app_file_src_script=ec_cnv:to_list(AppFileSrcScript)}.
+    AppInfo#app_info_t{app_file_src_script=rebar_utils:to_list(AppFileSrcScript)}.
 
 %% @doc finds the .app file for an app, if any.
 -spec app_file(t()) -> file:filename_all() | undefined.
 app_file(#app_info_t{app_file=undefined, out_dir=Dir, name=Name}) ->
-    AppFile = filename:join([ec_cnv:to_list(Dir), "ebin", ec_cnv:to_list(Name)++".app"]),
+    AppFile = filename:join([rebar_utils:to_list(Dir), "ebin", rebar_utils:to_list(Name)++".app"]),
     case filelib:is_file(AppFile) of
         true ->
             AppFile;
@@ -317,7 +317,7 @@ app_details(AppInfo=#app_info_t{app_details=[]}) ->
                 rebar_file_utils:try_consult(AppFile)
             catch
                 throw:{error, {Module, Reason}} ->
-                    ?DEBUG("Warning, falling back to .app.src because of: ~s",
+                    ?DEBUG("Warning, falling back to .app.src because of: ~ts",
                           [Module:format_error(Reason)]),
                     rebar_file_utils:try_consult(app_file_src(AppInfo))
             end
@@ -404,10 +404,10 @@ dir(#app_info_t{dir=Dir}) ->
 %% @doc sets the directory that contains the app.
 -spec dir(t(), file:name()) -> t().
 dir(AppInfo=#app_info_t{out_dir=undefined}, Dir) ->
-    AppInfo#app_info_t{dir=ec_cnv:to_list(Dir),
-                       out_dir=ec_cnv:to_list(Dir)};
+    AppInfo#app_info_t{dir=rebar_utils:to_list(Dir),
+                       out_dir=rebar_utils:to_list(Dir)};
 dir(AppInfo=#app_info_t{}, Dir) ->
-    AppInfo#app_info_t{dir=ec_cnv:to_list(Dir)}.
+    AppInfo#app_info_t{dir=rebar_utils:to_list(Dir)}.
 
 %% @doc returns the directory where build artifacts for the app
 %% should go
@@ -419,17 +419,17 @@ out_dir(#app_info_t{out_dir=OutDir}) ->
 %% should go
 -spec out_dir(t(), file:name()) -> t().
 out_dir(AppInfo=#app_info_t{}, OutDir) ->
-    AppInfo#app_info_t{out_dir=ec_cnv:to_list(OutDir)}.
+    AppInfo#app_info_t{out_dir=rebar_utils:to_list(OutDir)}.
 
 %% @doc gets the directory where ebin files for the app should go
 -spec ebin_dir(t()) -> file:name().
 ebin_dir(#app_info_t{out_dir=OutDir}) ->
-    ec_cnv:to_list(filename:join(OutDir, "ebin")).
+    rebar_utils:to_list(filename:join(OutDir, "ebin")).
 
 %% @doc gets the directory where private files for the app should go
 -spec priv_dir(t()) -> file:name().
 priv_dir(#app_info_t{out_dir=OutDir}) ->
-    ec_cnv:to_list(filename:join(OutDir, "priv")).
+    rebar_utils:to_list(filename:join(OutDir, "priv")).
 
 %% @doc returns whether the app is source app or a package app.
 -spec resource_type(t()) -> pkg | src.
@@ -519,7 +519,7 @@ all(Dir, Context, [File|Artifacts]) ->
     FilePath = filename:join(Dir, rebar_templater:render(File, Context)),
     case filelib:is_regular(FilePath) of
         false ->
-            ?DEBUG("Missing artifact ~s", [FilePath]),
+            ?DEBUG("Missing artifact ~ts", [FilePath]),
             {false, File};
         true ->
             all(Dir, Context, Artifacts)
diff --git a/src/rebar_app_utils.erl b/src/rebar_app_utils.erl
index 7154999..9422240 100644
--- a/src/rebar_app_utils.erl
+++ b/src/rebar_app_utils.erl
@@ -145,7 +145,7 @@ parse_dep(Dep, Parent, DepsDir, State, Locks, Level) ->
                Dep ->
                    Dep
            end,
-    case lists:keyfind(ec_cnv:to_binary(Name), 1, Locks) of
+    case lists:keyfind(rebar_utils:to_binary(Name), 1, Locks) of
         false ->
             parse_dep(Parent, Dep, DepsDir, false, State);
         LockedDep ->
@@ -167,18 +167,20 @@ parse_dep(Dep, Parent, DepsDir, State, Locks, Level) ->
       IsLock :: boolean(),
       State :: rebar_state:t().
 parse_dep(Parent, {Name, Vsn, {pkg, PkgName}}, DepsDir, IsLock, State) ->
-    {PkgName1, PkgVsn} = {ec_cnv:to_binary(PkgName), ec_cnv:to_binary(Vsn)},
+    {PkgName1, PkgVsn} = {rebar_utils:to_binary(PkgName),
+                          rebar_utils:to_binary(Vsn)},
     dep_to_app(Parent, DepsDir, Name, PkgVsn, {pkg, PkgName1, PkgVsn, undefined}, IsLock, State);
 parse_dep(Parent, {Name, {pkg, PkgName}}, DepsDir, IsLock, State) ->
     %% Package dependency with different package name from app name
-    dep_to_app(Parent, DepsDir, Name, undefined, {pkg, ec_cnv:to_binary(PkgName), undefined, undefined}, IsLock, State);
+    dep_to_app(Parent, DepsDir, Name, undefined, {pkg, rebar_utils:to_binary(PkgName), undefined, undefined}, IsLock, State);
 parse_dep(Parent, {Name, Vsn}, DepsDir, IsLock, State) when is_list(Vsn); is_binary(Vsn) ->
     %% Versioned Package dependency
-    {PkgName, PkgVsn} = {ec_cnv:to_binary(Name), ec_cnv:to_binary(Vsn)},
+    {PkgName, PkgVsn} = {rebar_utils:to_binary(Name),
+                         rebar_utils:to_binary(Vsn)},
     dep_to_app(Parent, DepsDir, PkgName, PkgVsn, {pkg, PkgName, PkgVsn, undefined}, IsLock, State);
 parse_dep(Parent, Name, DepsDir, IsLock, State) when is_atom(Name); is_binary(Name) ->
     %% Unversioned package dependency
-    dep_to_app(Parent, DepsDir, ec_cnv:to_binary(Name), undefined, {pkg, ec_cnv:to_binary(Name), undefined, undefined}, IsLock, State);
+    dep_to_app(Parent, DepsDir, rebar_utils:to_binary(Name), undefined, {pkg, rebar_utils:to_binary(Name), undefined, undefined}, IsLock, State);
 parse_dep(Parent, {Name, Source}, DepsDir, IsLock, State) when is_tuple(Source) ->
     dep_to_app(Parent, DepsDir, Name, [], Source, IsLock, State);
 parse_dep(Parent, {Name, _Vsn, Source}, DepsDir, IsLock, State) when is_tuple(Source) ->
@@ -212,12 +214,12 @@ parse_dep(_, Dep, _, _, _) ->
       IsLock :: boolean(),
       State :: rebar_state:t().
 dep_to_app(Parent, DepsDir, Name, Vsn, Source, IsLock, State) ->
-    CheckoutsDir = ec_cnv:to_list(rebar_dir:checkouts_dir(State, Name)),
+    CheckoutsDir = rebar_utils:to_list(rebar_dir:checkouts_dir(State, Name)),
     AppInfo = case rebar_app_info:discover(CheckoutsDir) of
                         {ok, App} ->
                             rebar_app_info:source(rebar_app_info:is_checkout(App, true), checkout);
                         not_found ->
-                            Dir = ec_cnv:to_list(filename:join(DepsDir, Name)),
+                            Dir = rebar_utils:to_list(filename:join(DepsDir, Name)),
                             {ok, AppInfo0} =
                                 case rebar_app_info:discover(Dir) of
                                     {ok, App} ->
@@ -275,7 +277,7 @@ fetch_checksum(PkgName, PkgVsn, Hash, State) ->
         rebar_packages:registry_checksum({pkg, PkgName, PkgVsn, Hash}, State)
     catch
         _:_ ->
-            ?INFO("Package ~s-~s not found. Fetching registry updates and trying again...", [PkgName, PkgVsn]),
+            ?INFO("Package ~ts-~ts not found. Fetching registry updates and trying again...", [PkgName, PkgVsn]),
             {ok, _} = rebar_prv_update:do(State),
             rebar_packages:registry_checksum({pkg, PkgName, PkgVsn, Hash}, State)
     end.
@@ -283,7 +285,7 @@ fetch_checksum(PkgName, PkgVsn, Hash, State) ->
 %% @doc convert a given exception's payload into an io description.
 -spec format_error(any()) -> iolist().
 format_error({missing_package, Package}) ->
-    io_lib:format("Package not found in registry: ~s", [Package]);
+    io_lib:format("Package not found in registry: ~ts", [Package]);
 format_error({parse_dep, Dep}) ->
     io_lib:format("Failed parsing dep ~p", [Dep]);
 format_error(Error) ->
@@ -302,7 +304,7 @@ get_package(Dep, Vsn, State) ->
         {ok, HighestDepVsn} ->
             {Dep, HighestDepVsn};
         none ->
-            throw(?PRV_ERROR({missing_package, ec_cnv:to_binary(Dep)}))
+            throw(?PRV_ERROR({missing_package, rebar_utils:to_binary(Dep)}))
     end.
 
 %% @private checks that all the beam files have been properly
@@ -310,7 +312,7 @@ get_package(Dep, Vsn, State) ->
 -spec has_all_beams(file:filename_all(), [module()]) ->
     true | ?PRV_ERROR({missing_module, module()}).
 has_all_beams(EbinDir, [Module | ModuleList]) ->
-    BeamFile = filename:join([EbinDir, ec_cnv:to_list(Module) ++ ".beam"]),
+    BeamFile = filename:join([EbinDir, rebar_utils:to_list(Module) ++ ".beam"]),
     case filelib:is_file(BeamFile) of
         true ->
             has_all_beams(EbinDir, ModuleList);
diff --git a/src/rebar_base_compiler.erl b/src/rebar_base_compiler.erl
index 480e49c..3f273f1 100644
--- a/src/rebar_base_compiler.erl
+++ b/src/rebar_base_compiler.erl
@@ -199,15 +199,15 @@ compile_each([], _Config, _CompileFn) ->
 compile_each([Source | Rest], Config, CompileFn) ->
     case CompileFn(Source, Config) of
         ok ->
-            ?DEBUG("~sCompiled ~s", [rebar_utils:indent(1), filename:basename(Source)]);
+            ?DEBUG("~tsCompiled ~ts", [rebar_utils:indent(1), filename:basename(Source)]);
         {ok, Warnings} ->
             report(Warnings),
-            ?DEBUG("~sCompiled ~s", [rebar_utils:indent(1), filename:basename(Source)]);
+            ?DEBUG("~tsCompiled ~ts", [rebar_utils:indent(1), filename:basename(Source)]);
         skipped ->
-            ?DEBUG("~sSkipped ~s", [rebar_utils:indent(1), filename:basename(Source)]);
+            ?DEBUG("~tsSkipped ~ts", [rebar_utils:indent(1), filename:basename(Source)]);
         Error ->
             NewSource = format_error_source(Source, Config),
-            ?ERROR("Compiling ~s failed", [NewSource]),
+            ?ERROR("Compiling ~ts failed", [NewSource]),
             maybe_report(Error),
             ?DEBUG("Compilation failed: ~p", [Error]),
             ?FAIL
@@ -258,7 +258,7 @@ maybe_report(_) ->
 %% @private Outputs a bunch of strings, including a newline
 -spec report([string()]) -> ok.
 report(Messages) ->
-    lists:foreach(fun(Msg) -> io:format("~s~n", [Msg]) end, Messages).
+    lists:foreach(fun(Msg) -> io:format("~ts~n", [Msg]) end, Messages).
 
 %% private format compiler errors into proper outputtable strings
 -spec format_errors(_, Extra, [err_or_warn()]) -> [string()] when
@@ -274,10 +274,10 @@ format_errors(_MainSource, Extra, Errors) ->
       Extra :: string().
 format_error(Source, Extra, {{Line, Column}, Mod, Desc}) ->
     ErrorDesc = Mod:format_error(Desc),
-    ?FMT("~s:~w:~w: ~s~s~n", [Source, Line, Column, Extra, ErrorDesc]);
+    ?FMT("~ts:~w:~w: ~ts~ts~n", [Source, Line, Column, Extra, ErrorDesc]);
 format_error(Source, Extra, {Line, Mod, Desc}) ->
     ErrorDesc = Mod:format_error(Desc),
-    ?FMT("~s:~w: ~s~s~n", [Source, Line, Extra, ErrorDesc]);
+    ?FMT("~ts:~w: ~ts~ts~n", [Source, Line, Extra, ErrorDesc]);
 format_error(Source, Extra, {Mod, Desc}) ->
     ErrorDesc = Mod:format_error(Desc),
-    ?FMT("~s: ~s~s~n", [Source, Extra, ErrorDesc]).
+    ?FMT("~ts: ~ts~ts~n", [Source, Extra, ErrorDesc]).
diff --git a/src/rebar_config.erl b/src/rebar_config.erl
index 82ff0d9..7316d83 100644
--- a/src/rebar_config.erl
+++ b/src/rebar_config.erl
@@ -120,7 +120,7 @@ write_lock_file(LockFile, Locks) ->
             file:write_file(LockFile, io_lib:format("~p.~n", [NewLocks]));
         _ ->
             file:write_file(LockFile,
-                            io_lib:format("{~p,~n~p}.~n[~n~s~n].~n",
+                            io_lib:format("{~p,~n~p}.~n[~n~ts~n].~n",
                                           [?CONFIG_VERSION, NewLocks,
                                            format_attrs(Attrs)]))
     end.
@@ -359,7 +359,7 @@ check_newly_added_({Name, Source}, LockedDeps) ->
             false
     end;
 check_newly_added_(Dep, LockedDeps) when is_atom(Dep) ->
-    Name = ec_cnv:to_binary(Dep),
+    Name = rebar_utils:to_binary(Dep),
     case lists:keyfind(Name, 1, LockedDeps) of
         false ->
             {true, Name};
@@ -368,8 +368,8 @@ check_newly_added_(Dep, LockedDeps) when is_atom(Dep) ->
                 0 ->
                     {true, Name};
                 _ ->
-                    ?WARN("Newly added dep ~s is locked at a lower level. "
-                          "If you really want to unlock it, use 'rebar3 upgrade ~s'",
+                    ?WARN("Newly added dep ~ts is locked at a lower level. "
+                          "If you really want to unlock it, use 'rebar3 upgrade ~ts'",
                           [Name, Name]),
                     false
             end
diff --git a/src/rebar_core.erl b/src/rebar_core.erl
index 14c4906..3ef7a0d 100644
--- a/src/rebar_core.erl
+++ b/src/rebar_core.erl
@@ -119,11 +119,11 @@ process_command(State, Command) ->
                             State2 = rebar_state:command_parsed_args(State1, Args),
                             do(TargetProviders, State2);
                         {error, {invalid_option, Option}} ->
-                            {error, io_lib:format("Invalid option ~s on task ~p", [Option, Command])};
+                            {error, io_lib:format("Invalid option ~ts on task ~p", [Option, Command])};
                         {error, {invalid_option_arg, {Option, Arg}}} ->
-                            {error, io_lib:format("Invalid argument ~s to option ~s", [Arg, Option])};
+                            {error, io_lib:format("Invalid argument ~ts to option ~ts", [Arg, Option])};
                         {error, {missing_option_arg, Option}} ->
-                            {error, io_lib:format("Missing argument to option ~s", [Option])}
+                            {error, io_lib:format("Missing argument to option ~ts", [Option])}
                     end
             end
     end.
@@ -173,6 +173,6 @@ do([ProviderName | Rest], State) ->
 %% @doc convert a given exception's payload into an io description.
 -spec format_error(any()) -> iolist().
 format_error({bad_provider_namespace, {Namespace, Name}}) ->
-    io_lib:format("Undefined command ~s in namespace ~s", [Name, Namespace]);
+    io_lib:format("Undefined command ~ts in namespace ~ts", [Name, Namespace]);
 format_error({bad_provider_namespace, Name}) ->
-    io_lib:format("Undefined command ~s", [Name]).
+    io_lib:format("Undefined command ~ts", [Name]).
diff --git a/src/rebar_dialyzer_format.erl b/src/rebar_dialyzer_format.erl
index be8cc48..7cf4e63 100644
--- a/src/rebar_dialyzer_format.erl
+++ b/src/rebar_dialyzer_format.erl
@@ -31,7 +31,7 @@ format_warnings(Opts, Warnings) ->
 format_warning_(_Opts, Warning = {_Tag, {File, Line}, Msg}, {File, Acc}) ->
     try
         String = message_to_string(Msg),
-        {File, [lists:flatten(fmt("~!c~4w~!!: ~s", [Line, String])) | Acc]}
+        {File, [lists:flatten(fmt("~!c~4w~!!: ~ts", [Line, String])) | Acc]}
     catch
         Error:Reason ->
             ?DEBUG("Failed to pretty format warning: ~p:~p",
@@ -47,11 +47,11 @@ format_warning_(Opts, Warning = {_Tag, {SrcFile, Line}, Msg}, {_LastFile, Acc})
         Dir = filename:dirname(File),
         Root = filename:rootname(Base),
         Ext = filename:extension(Base),
-        Path = re:replace(Dir, "^.*/_build/", "_build/", [{return, list}]),
-        Base1 = fmt("~!_c~s~!!~!__~s", [Root, Ext]),
-        F = fmt("~!__~s", [filename:join(Path, Base1)]),
+        Path = re:replace(Dir, "^.*/_build/", "_build/", [{return, list}, unicode]),
+        Base1 = fmt("~!_c~ts~!!~!__~ts", [Root, Ext]),
+        F = fmt("~!__~ts", [filename:join(Path, Base1)]),
         String = message_to_string(Msg),
-        {SrcFile, [lists:flatten(fmt("~n~s~n~!c~4w~!!: ~s", [F, Line, String])) | Acc]}
+        {SrcFile, [lists:flatten(fmt("~n~ts~n~!c~4w~!!: ~ts", [F, Line, String])) | Acc]}
     catch
         Error:Reason ->
             ?DEBUG("Failed to pretty format warning: ~p:~p~n~p",
@@ -72,53 +72,53 @@ fmt(Fmt, Args) ->
 %%----- Warnings for general discrepancies ----------------
 message_to_string({apply, [Args, ArgNs, FailReason,
                            SigArgs, SigRet, Contract]}) ->
-    fmt("~!^Fun application with arguments ~!!~s ",
+    fmt("~!^Fun application with arguments ~!!~ts ",
         [bad_arg(ArgNs, Args)]) ++
         call_or_apply_to_string(ArgNs, FailReason, SigArgs, SigRet, Contract);
 message_to_string({app_call, [M, F, Args, Culprit, ExpectedType, FoundType]}) ->
-    fmt("~!^The call~!! ~s:~s~s ~!^requires that"
-        "~!! ~s ~!^is of type ~!g~s~!^ not ~!r~s",
+    fmt("~!^The call~!! ~ts:~ts~ts ~!^requires that"
+        "~!! ~ts ~!^is of type ~!g~ts~!^ not ~!r~ts",
         [M, F, Args, Culprit, ExpectedType, FoundType]);
 message_to_string({bin_construction, [Culprit, Size, Seg, Type]}) ->
-    fmt("~!^Binary construction will fail since the ~!b~s~!^ field~!!"
-        " ~s~!^ in segment~!! ~s~!^ has type~!! ~s",
+    fmt("~!^Binary construction will fail since the ~!b~ts~!^ field~!!"
+        " ~ts~!^ in segment~!! ~ts~!^ has type~!! ~ts",
         [Culprit, Size, Seg, Type]);
 message_to_string({call, [M, F, Args, ArgNs, FailReason,
                           SigArgs, SigRet, Contract]}) ->
-    fmt("~!^The call~!! ~w:~w~s ", [M, F, bad_arg(ArgNs, Args)]) ++
+    fmt("~!^The call~!! ~w:~w~ts ", [M, F, bad_arg(ArgNs, Args)]) ++
         call_or_apply_to_string(ArgNs, FailReason, SigArgs, SigRet, Contract);
 message_to_string({call_to_missing, [M, F, A]}) ->
     fmt("~!^Call to missing or unexported function ~!!~w:~w/~w",
         [M, F, A]);
 message_to_string({exact_eq, [Type1, Op, Type2]}) ->
-    fmt("~!^The test ~!!~s ~s ~s~!^ can never evaluate to 'true'",
+    fmt("~!^The test ~!!~ts ~ts ~ts~!^ can never evaluate to 'true'",
         [Type1, Op, Type2]);
 message_to_string({fun_app_args, [Args, Type]}) ->
-    fmt("~!^Fun application with arguments ~!!~s~!^ will fail"
-        " since the function has type ~!!~s", [Args, Type]);
+    fmt("~!^Fun application with arguments ~!!~ts~!^ will fail"
+        " since the function has type ~!!~ts", [Args, Type]);
 message_to_string({fun_app_no_fun, [Op, Type, Arity]}) ->
-    fmt("~!^Fun application will fail since ~!!~s ~!^::~!! ~s"
+    fmt("~!^Fun application will fail since ~!!~ts ~!^::~!! ~ts"
         " is not a function of arity ~!!~w", [Op, Type, Arity]);
 message_to_string({guard_fail, []}) ->
     "~!^Clause guard cannot succeed.~!!";
 message_to_string({guard_fail, [Arg1, Infix, Arg2]}) ->
-    fmt("~!^Guard test ~!!~s ~s ~s~!^ can never succeed",
+    fmt("~!^Guard test ~!!~ts ~ts ~ts~!^ can never succeed",
         [Arg1, Infix, Arg2]);
 message_to_string({neg_guard_fail, [Arg1, Infix, Arg2]}) ->
-    fmt("~!^Guard test not(~!!~s ~s ~s~!^) can never succeed",
+    fmt("~!^Guard test not(~!!~ts ~ts ~ts~!^) can never succeed",
         [Arg1, Infix, Arg2]);
 message_to_string({guard_fail, [Guard, Args]}) ->
-    fmt("~!^Guard test ~!!~w~s~!^ can never succeed",
+    fmt("~!^Guard test ~!!~w~ts~!^ can never succeed",
         [Guard, Args]);
 message_to_string({neg_guard_fail, [Guard, Args]}) ->
-    fmt("~!^Guard test not(~!!~w~s~!^) can never succeed",
+    fmt("~!^Guard test not(~!!~w~ts~!^) can never succeed",
         [Guard, Args]);
 message_to_string({guard_fail_pat, [Pat, Type]}) ->
-    fmt("~!^Clause guard cannot succeed. The ~!!~s~!^ was matched"
-        " against the type ~!!~s", [Pat, Type]);
+    fmt("~!^Clause guard cannot succeed. The ~!!~ts~!^ was matched"
+        " against the type ~!!~ts", [Pat, Type]);
 message_to_string({improper_list_constr, [TlType]}) ->
     fmt("~!^Cons will produce an improper list"
-        " since its ~!b2~!!nd~!^ argument is~!! ~s", [TlType]);
+        " since its ~!b2~!!nd~!^ argument is~!! ~ts", [TlType]);
 message_to_string({no_return, [Type|Name]}) ->
     NameString =
         case Name of
@@ -126,59 +126,59 @@ message_to_string({no_return, [Type|Name]}) ->
             [F, A] -> fmt("~!^Function ~!r~w/~w ", [F, A])
         end,
     case Type of
-        no_match -> fmt("~s~!^has no clauses that will ever match",[NameString]);
-        only_explicit -> fmt("~s~!^only terminates with explicit exception", [NameString]);
-        only_normal -> fmt("~s~!^has no local return", [NameString]);
-        both -> fmt("~s~!^has no local return", [NameString])
+        no_match -> fmt("~ts~!^has no clauses that will ever match",[NameString]);
+        only_explicit -> fmt("~ts~!^only terminates with explicit exception", [NameString]);
+        only_normal -> fmt("~ts~!^has no local return", [NameString]);
+        both -> fmt("~ts~!^has no local return", [NameString])
     end;
 message_to_string({record_constr, [RecConstr, FieldDiffs]}) ->
-    fmt("~!^Record construction ~!!~s~!^ violates the"
-        " declared type of field ~!!~s", [RecConstr, FieldDiffs]);
+    fmt("~!^Record construction ~!!~ts~!^ violates the"
+        " declared type of field ~!!~ts", [RecConstr, FieldDiffs]);
 message_to_string({record_constr, [Name, Field, Type]}) ->
     fmt("~!^Record construction violates the declared type for ~!!#~w{}~!^"
-        " since ~!!~s~!^ cannot be of type ~!!~s",
+        " since ~!!~ts~!^ cannot be of type ~!!~ts",
         [Name, Field, Type]);
 message_to_string({record_matching, [String, Name]}) ->
-    fmt("~!^The ~!!~s~!^ violates the"
+    fmt("~!^The ~!!~ts~!^ violates the"
         " declared type for ~!!#~w{}", [String, Name]);
 message_to_string({record_match, [Pat, Type]}) ->
-    fmt("~!^Matching of ~!!~s~!^ tagged with a record name violates the"
-        " declared type of ~!!~s", [Pat, Type]);
+    fmt("~!^Matching of ~!!~ts~!^ tagged with a record name violates the"
+        " declared type of ~!!~ts", [Pat, Type]);
 message_to_string({pattern_match, [Pat, Type]}) ->
-    fmt("~!^The ~s~!^ can never match the type ~!g~s",
+    fmt("~!^The ~ts~!^ can never match the type ~!g~ts",
         [bad_pat(Pat), Type]);
 message_to_string({pattern_match_cov, [Pat, Type]}) ->
-    fmt("~!^The ~s~!^ can never match since previous"
-        " clauses completely covered the type ~!g~s",
+    fmt("~!^The ~ts~!^ can never match since previous"
+        " clauses completely covered the type ~!g~ts",
         [bad_pat(Pat), Type]);
 message_to_string({unmatched_return, [Type]}) ->
-    fmt("~!^Expression produces a value of type ~!!~s~!^,"
+    fmt("~!^Expression produces a value of type ~!!~ts~!^,"
         " but this value is unmatched", [Type]);
 message_to_string({unused_fun, [F, A]}) ->
     fmt("~!^Function ~!r~w/~w~!!~!^ will never be called", [F, A]);
 %%----- Warnings for specs and contracts -------------------
 message_to_string({contract_diff, [M, F, _A, Contract, Sig]}) ->
-    fmt("~!^Type specification ~!!~w:~w~s~!^"
-        " is not equal to the success typing: ~!!~w:~w~s",
+    fmt("~!^Type specification ~!!~w:~w~ts~!^"
+        " is not equal to the success typing: ~!!~w:~w~ts",
         [M, F, Contract, M, F, Sig]);
 message_to_string({contract_subtype, [M, F, _A, Contract, Sig]}) ->
-    fmt("~!^Type specification ~!!~w:~w~s~!^"
-        " is a subtype of the success typing: ~!!~w:~w~s",
+    fmt("~!^Type specification ~!!~w:~w~ts~!^"
+        " is a subtype of the success typing: ~!!~w:~w~ts",
         [M, F, Contract, M, F, Sig]);
 message_to_string({contract_supertype, [M, F, _A, Contract, Sig]}) ->
-    fmt("~!^Type specification ~!!~w:~w~s~!^"
-        " is a supertype of the success typing: ~!!~w:~w~s",
+    fmt("~!^Type specification ~!!~w:~w~ts~!^"
+        " is a supertype of the success typing: ~!!~w:~w~ts",
         [M, F, Contract, M, F, Sig]);
 message_to_string({contract_range, [Contract, M, F, ArgStrings, Line, CRet]}) ->
-    fmt("~!^The contract ~!!~w:~w~s~!^ cannot be right because the"
-        " inferred return for ~!!~w~s~!^ on line ~!!~w~!^ is ~!!~s",
+    fmt("~!^The contract ~!!~w:~w~ts~!^ cannot be right because the"
+        " inferred return for ~!!~w~ts~!^ on line ~!!~w~!^ is ~!!~ts",
         [M, F, Contract, F, ArgStrings, Line, CRet]);
 message_to_string({invalid_contract, [M, F, A, Sig]}) ->
     fmt("~!^Invalid type specification for function~!! ~w:~w/~w."
-        "~!^ The success typing is~!! ~s", [M, F, A, Sig]);
+        "~!^ The success typing is~!! ~ts", [M, F, A, Sig]);
 message_to_string({extra_range, [M, F, A, ExtraRanges, SigRange]}) ->
     fmt("~!^The specification for ~!!~w:~w/~w~!^ states that the function"
-        " might also return ~!!~s~!^ but the inferred return is ~!!~s",
+        " might also return ~!!~ts~!^ but the inferred return is ~!!~ts",
         [M, F, A, ExtraRanges, SigRange]);
 message_to_string({overlapping_contract, [M, F, A]}) ->
     fmt("~!^Overloaded contract for ~!!~w:~w/~w~!^ has overlapping"
@@ -189,62 +189,62 @@ message_to_string({spec_missing_fun, [M, F, A]}) ->
         [M, F, A]);
 %%----- Warnings for opaque type violations -------------------
 message_to_string({call_with_opaque, [M, F, Args, ArgNs, ExpArgs]}) ->
-    fmt("~!^The call ~!!~w:~w~s~!^ contains ~!!~s~!^ when ~!!~s",
+    fmt("~!^The call ~!!~w:~w~ts~!^ contains ~!!~ts~!^ when ~!!~ts",
         [M, F, bad_arg(ArgNs, Args), form_positions(ArgNs), form_expected(ExpArgs)]);
 message_to_string({call_without_opaque, [M, F, Args, [{N,_,_}|_] = ExpectedTriples]}) ->
-    fmt("~!^The call ~!!~w:~w~s ~!^does not have~!! ~s",
+    fmt("~!^The call ~!!~w:~w~ts ~!^does not have~!! ~ts",
         [M, F, bad_arg(N, Args), form_expected_without_opaque(ExpectedTriples)]);
 message_to_string({opaque_eq, [Type, _Op, OpaqueType]}) ->
-    fmt("~!^Attempt to test for equality between a term of type ~!!~s~!^"
-        " and a term of opaque type ~!!~s", [Type, OpaqueType]);
+    fmt("~!^Attempt to test for equality between a term of type ~!!~ts~!^"
+        " and a term of opaque type ~!!~ts", [Type, OpaqueType]);
 message_to_string({opaque_guard, [Arg1, Infix, Arg2, ArgNs]}) ->
-    fmt("~!^Guard test ~!!~s ~s ~s~!^ contains ~!!~s",
+    fmt("~!^Guard test ~!!~ts ~ts ~ts~!^ contains ~!!~ts",
         [Arg1, Infix, Arg2, form_positions(ArgNs)]);
 message_to_string({opaque_guard, [Guard, Args]}) ->
-    fmt("~!^Guard test ~!!~w~s~!^ breaks the opaqueness of its"
+    fmt("~!^Guard test ~!!~w~ts~!^ breaks the opaqueness of its"
         " argument", [Guard, Args]);
 message_to_string({opaque_match, [Pat, OpaqueType, OpaqueTerm]}) ->
     Term = if OpaqueType =:= OpaqueTerm -> "the term";
               true -> OpaqueTerm
            end,
-    fmt("~!^The attempt to match a term of type ~!!~s~!^ against the"
-        "~!! ~s~!^ breaks the opaqueness of ~!!~s",
+    fmt("~!^The attempt to match a term of type ~!!~ts~!^ against the"
+        "~!! ~ts~!^ breaks the opaqueness of ~!!~ts",
         [OpaqueType, Pat, Term]);
 message_to_string({opaque_neq, [Type, _Op, OpaqueType]}) ->
-    fmt("~!^Attempt to test for inequality between a term of type ~!!~s"
-        "~!^ and a term of opaque type ~!!~s", [Type, OpaqueType]);
+    fmt("~!^Attempt to test for inequality between a term of type ~!!~ts"
+        "~!^ and a term of opaque type ~!!~ts", [Type, OpaqueType]);
 message_to_string({opaque_type_test, [Fun, Args, Arg, ArgType]}) ->
-    fmt("~!^The type test ~!!~s~s~!^ breaks the opaqueness of the term "
-        "~!!~s~s", [Fun, Args, Arg, ArgType]);
+    fmt("~!^The type test ~!!~ts~ts~!^ breaks the opaqueness of the term "
+        "~!!~ts~ts", [Fun, Args, Arg, ArgType]);
 message_to_string({opaque_size, [SizeType, Size]}) ->
-    fmt("~!^The size ~!!~s~!^ breaks the opaqueness of ~!!~s",
+    fmt("~!^The size ~!!~ts~!^ breaks the opaqueness of ~!!~ts",
         [SizeType, Size]);
 message_to_string({opaque_call, [M, F, Args, Culprit, OpaqueType]}) ->
-    fmt("~!^The call ~!!~s:~s~s~!^ breaks the opaqueness of the term~!!"
-        " ~s :: ~s", [M, F, Args, Culprit, OpaqueType]);
+    fmt("~!^The call ~!!~ts:~ts~ts~!^ breaks the opaqueness of the term~!!"
+        " ~ts :: ~ts", [M, F, Args, Culprit, OpaqueType]);
 %%----- Warnings for concurrency errors --------------------
 message_to_string({race_condition, [M, F, Args, Reason]}) ->
-    fmt("~!^The call ~!!~w:~w~s ~s", [M, F, Args, Reason]);
+    fmt("~!^The call ~!!~w:~w~ts ~ts", [M, F, Args, Reason]);
 %%----- Warnings for behaviour errors --------------------
 message_to_string({callback_type_mismatch, [B, F, A, ST, CT]}) ->
-    fmt("~!^The inferred return type of~!! ~w/~w (~s) ~!^"
-        "has nothing in common with~!! ~s, ~!^which is the expected"
+    fmt("~!^The inferred return type of~!! ~w/~w (~ts) ~!^"
+        "has nothing in common with~!! ~ts, ~!^which is the expected"
         " return type for the callback of~!! ~w ~!^behaviour",
         [F, A, ST, CT, B]);
 message_to_string({callback_arg_type_mismatch, [B, F, A, N, ST, CT]}) ->
-    fmt("~!^The inferred type for the~!! ~s ~!^argument of~!!"
-        " ~w/~w (~s) ~!^is not a supertype of~!! ~s~!^, which is"
+    fmt("~!^The inferred type for the~!! ~ts ~!^argument of~!!"
+        " ~w/~w (~ts) ~!^is not a supertype of~!! ~ts~!^, which is"
         "expected type for this argument in the callback of the~!! ~w "
         "~!^behaviour",
         [ordinal(N), F, A, ST, CT, B]);
 message_to_string({callback_spec_type_mismatch, [B, F, A, ST, CT]}) ->
-    fmt("~!^The return type ~!!~s~!^ in the specification of ~!!"
-        "~w/~w~!^ is not a subtype of ~!!~s~!^, which is the expected"
+    fmt("~!^The return type ~!!~ts~!^ in the specification of ~!!"
+        "~w/~w~!^ is not a subtype of ~!!~ts~!^, which is the expected"
         " return type for the callback of ~!!~w~!^ behaviour",
         [ST, F, A, CT, B]);
 message_to_string({callback_spec_arg_type_mismatch, [B, F, A, N, ST, CT]}) ->
-    fmt("~!^The specified type for the ~!!~s~!^ argument of ~!!"
-        "~w/~w (~s)~!^ is not a supertype of ~!!~s~!^, which is"
+    fmt("~!^The specified type for the ~!!~ts~!^ argument of ~!!"
+        "~w/~w (~ts)~!^ is not a supertype of ~!!~ts~!^, which is"
         " expected type for this argument in the callback of the ~!!~w"
         "~!^ behaviour", [ordinal(N), F, A, ST, CT, B]);
 message_to_string({callback_missing, [B, F, A]}) ->
@@ -274,26 +274,26 @@ call_or_apply_to_string(ArgNs, FailReason, SigArgs, SigRet,
                 true ->
                     %% We do not know which argument(s) caused the failure
                     fmt("~!^will never return since the success typing arguments"
-                        " are ~!!~s", [SigArgs]);
+                        " are ~!!~ts", [SigArgs]);
                 false ->
                     fmt("~!^will never return since it differs in the~!!"
-                        " ~s ~!^argument from the success typing"
-                        " arguments:~!! ~s",
+                        " ~ts ~!^argument from the success typing"
+                        " arguments:~!! ~ts",
                         [PositionString, good_arg(ArgNs, SigArgs)])
             end;
         only_contract ->
             case (ArgNs =:= []) orelse IsOverloaded of
                 true ->
                     %% We do not know which arguments caused the failure
-                    fmt("~!^breaks the contract~!! ~s", [good_arg(ArgNs, Contract)]);
+                    fmt("~!^breaks the contract~!! ~ts", [good_arg(ArgNs, Contract)]);
                 false ->
-                    fmt("~!^breaks the contract~!! ~s ~!^in the~!!"
-                        " ~s ~!^argument",
+                    fmt("~!^breaks the contract~!! ~ts ~!^in the~!!"
+                        " ~ts ~!^argument",
                         [good_arg(ArgNs, Contract), PositionString])
             end;
         both ->
             fmt("~!^will never return since the success typing is "
-                "~!!~s ~!^->~!! ~s ~!^and the contract is ~!!~s",
+                "~!!~ts ~!^->~!! ~ts ~!^and the contract is ~!!~ts",
                 [good_arg(ArgNs, SigArgs), SigRet,
                  good_arg(ArgNs, Contract)])
     end.
@@ -301,8 +301,8 @@ call_or_apply_to_string(ArgNs, FailReason, SigArgs, SigRet,
 form_positions(ArgNs) ->
     ArgS = form_position_string(ArgNs),
     case ArgNs of
-        [_] ->     fmt("~!^an opaque term as ~!!~s~!^ argument", [ArgS]);
-        [_,_|_] -> fmt("~!^opaque terms as ~!!~s~!^ arguments", [ArgS])
+        [_] ->     fmt("~!^an opaque term as ~!!~ts~!^ argument", [ArgS]);
+        [_,_|_] -> fmt("~!^opaque terms as ~!!~ts~!^ arguments", [ArgS])
     end.
 
 %% We know which positions N are to blame;
@@ -310,9 +310,9 @@ form_positions(ArgNs) ->
 form_expected_without_opaque([{N, T, TStr}]) ->
     FStr = case erl_types:t_is_opaque(T) of
                true  ->
-                   "~!^an opaque term of type~!g ~s ~!^as ";
+                   "~!^an opaque term of type~!g ~ts ~!^as ";
                false ->
-                   "~!^a term of type ~!g~s ~!^(with opaque subterms) as "
+                   "~!^a term of type ~!g~ts ~!^(with opaque subterms) as "
            end ++ form_position_string([N]) ++ "~!^ argument",
     fmt(FStr, [TStr]);
 
@@ -325,9 +325,9 @@ form_expected(ExpectedArgs) ->
         [T] ->
             TS = erl_types:t_to_string(T),
             case erl_types:t_is_opaque(T) of
-                true  -> fmt("~!^an opaque term of type ~!!~s~!^ is"
+                true  -> fmt("~!^an opaque term of type ~!!~ts~!^ is"
                              " expected", [TS]);
-                false -> fmt("~!^a structured term of type ~!!~s~!^ is"
+                false -> fmt("~!^a structured term of type ~!!~ts~!^ is"
                              " expected", [TS])
             end;
         [_,_|_] -> fmt("~!^terms of different types are expected in these"
@@ -340,7 +340,7 @@ form_position_string(ArgNs) ->
         [N1] -> ordinal(N1);
         [_,_|_] ->
             [Last|Prevs] = lists:reverse(ArgNs),
-            ", " ++ Head = lists:flatten([fmt(", ~s",[ordinal(N)]) ||
+            ", " ++ Head = lists:flatten([fmt(", ~ts",[ordinal(N)]) ||
                                              N <- lists:reverse(Prevs)]),
             Head ++ " and " ++ ordinal(Last)
     end.
@@ -352,11 +352,11 @@ ordinal(N) when is_integer(N) -> fmt("~!B~w~!!th", [N]).
 
 %% Format a pattern ad highlight errorous part in red.
 bad_pat("pattern " ++ P) ->
-    fmt("pattern ~!r~s",[P]);
+    fmt("pattern ~!r~ts",[P]);
 bad_pat("variable " ++ P) ->
-    fmt("variable ~!r~s",[P]);
+    fmt("variable ~!r~ts",[P]);
 bad_pat(P) ->
-    fmt("~!r~s",[P]).
+    fmt("~!r~ts",[P]).
 
 
 bad_arg(N, Args) ->
@@ -378,10 +378,10 @@ highlight([], _N, _C, Rest) ->
     Rest;
 
 highlight([N | Nr], N, g, [Arg | Rest]) ->
-    [fmt("~!g~s", [Arg]) | highlight(Nr, N+1, g, Rest)];
+    [fmt("~!g~ts", [Arg]) | highlight(Nr, N+1, g, Rest)];
 
 highlight([N | Nr], N, r, [Arg | Rest]) ->
-    [fmt("~!r~s", [Arg]) | highlight(Nr, N+1, r, Rest)];
+    [fmt("~!r~ts", [Arg]) | highlight(Nr, N+1, r, Rest)];
 
 highlight(Ns, N, C, [Arg | Rest]) ->
     [Arg | highlight(Ns, N + 1, C, Rest)].
diff --git a/src/rebar_digraph.erl b/src/rebar_digraph.erl
index a827735..776d7b8 100644
--- a/src/rebar_digraph.erl
+++ b/src/rebar_digraph.erl
@@ -53,9 +53,9 @@ add(Graph, {PkgName, Deps}) ->
     lists:foreach(fun(DepName) ->
                           Name1 = case DepName of
                                       {Name, _Vsn} ->
-                                          ec_cnv:to_binary(Name);
+                                          rebar_utils:to_binary(Name);
                                       Name ->
-                                          ec_cnv:to_binary(Name)
+                                          rebar_utils:to_binary(Name)
                                   end,
                           V3 = case digraph:vertex(Graph, Name1) of
                                    false ->
diff --git a/src/rebar_dir.erl b/src/rebar_dir.erl
index b61bfcc..d0c7805 100644
--- a/src/rebar_dir.erl
+++ b/src/rebar_dir.erl
@@ -41,7 +41,7 @@ base_dir(State) ->
 %% of profiles.
 -spec profile_dir(rebar_dict(), [atom()]) -> file:filename_all().
 profile_dir(Opts, Profiles) ->
-    {BaseDir, ProfilesStrings} = case [ec_cnv:to_list(P) || P <- Profiles] of
+    {BaseDir, ProfilesStrings} = case [rebar_utils:to_list(P) || P <- Profiles] of
         ["global" | _] -> {?MODULE:global_cache_dir(Opts), [""]};
         ["bootstrap", "default"] -> {rebar_opts:get(Opts, base_dir, ?DEFAULT_BASE_DIR), ["default"]};
         ["default"] -> {rebar_opts:get(Opts, base_dir, ?DEFAULT_BASE_DIR), ["default"]};
@@ -363,7 +363,7 @@ warn_source_format_once(Format) ->
             ok;
         true ->
             ?WARN("Invalid argument ~p for compiler_source_format - "
-                  "assuming ~s~n", [Format, ?DEFAULT_COMPILER_SOURCE_FORMAT])
+                  "assuming ~ts~n", [Format, ?DEFAULT_COMPILER_SOURCE_FORMAT])
     end.
 
 %% @private takes a filename and canonicalizes its path if it is a link.
diff --git a/src/rebar_erlc_compiler.erl b/src/rebar_erlc_compiler.erl
index 9157aba..94cbe13 100644
--- a/src/rebar_erlc_compiler.erl
+++ b/src/rebar_erlc_compiler.erl
@@ -92,7 +92,7 @@ compile(AppInfo) when element(1, AppInfo) == app_info_t ->
 %% @doc compile an individual application.
 -spec compile(rebar_app_info:t(), compile_opts()) -> ok.
 compile(AppInfo, CompileOpts) when element(1, AppInfo) == app_info_t ->
-    Dir = ec_cnv:to_list(rebar_app_info:out_dir(AppInfo)),
+    Dir = rebar_utils:to_list(rebar_app_info:out_dir(AppInfo)),
     RebarOpts = rebar_app_info:opts(AppInfo),
 
     SrcOpts = [check_last_mod,
@@ -237,8 +237,8 @@ clean(AppInfo) ->
 
     YrlFiles = rebar_utils:find_files(filename:join([AppDir, "src"]), ?RE_PREFIX".*\\.[x|y]rl\$"),
     rebar_file_utils:delete_each(
-      [ binary_to_list(iolist_to_binary(re:replace(F, "\\.[x|y]rl$", ".erl")))
-        || F <- YrlFiles ]),
+      [rebar_utils:to_list(re:replace(F, "\\.[x|y]rl$", ".erl", [unicode]))
+       || F <- YrlFiles]),
 
     BinDirs = ["ebin"|rebar_dir:extra_src_dirs(rebar_app_info:opts(AppInfo))],
     ok = clean_dirs(AppDir, BinDirs),
@@ -339,7 +339,7 @@ maybe_rm_beam_and_edge(G, OutDir, Source) ->
             false;
         false ->
             Target = target_base(OutDir, Source) ++ ".beam",
-            ?DEBUG("Source ~s is gone, deleting previous beam file if it exists ~s", [Source, Target]),
+            ?DEBUG("Source ~ts is gone, deleting previous beam file if it exists ~ts", [Source, Target]),
             file:delete(Target),
             digraph:del_vertex(G, Source),
             true
@@ -400,7 +400,7 @@ init_erlcinfo(InclDirs, Erls, Dir, OutDir) ->
     try restore_erlcinfo(G, InclDirs, Dir)
     catch
         _:_ ->
-            ?WARN("Failed to restore ~s file. Discarding it.~n", [erlcinfo_file(Dir)]),
+            ?WARN("Failed to restore ~ts file. Discarding it.~n", [erlcinfo_file(Dir)]),
             file:delete(erlcinfo_file(Dir))
     end,
     Dirs = source_and_include_dirs(InclDirs, Erls),
diff --git a/src/rebar_fetch.erl b/src/rebar_fetch.erl
index f5e5db5..f68a54d 100644
--- a/src/rebar_fetch.erl
+++ b/src/rebar_fetch.erl
@@ -41,7 +41,7 @@ download_source_(AppDir, Source, State) ->
     Resources = rebar_state:resources(State),
     Module = get_resource_type(Source, Resources),
     TmpDir = ec_file:insecure_mkdtemp(),
-    AppDir1 = ec_cnv:to_list(AppDir),
+    AppDir1 = rebar_utils:to_list(AppDir),
     case Module:download(TmpDir, Source, State) of
         {ok, _} ->
             ec_file:mkdir_p(AppDir1),
@@ -66,25 +66,25 @@ needs_update(AppDir, Source, State) ->
     end.
 
 format_error({bad_download, CachePath}) ->
-    io_lib:format("Download of package does not match md5sum from server: ~s", [CachePath]);
+    io_lib:format("Download of package does not match md5sum from server: ~ts", [CachePath]);
 format_error({unexpected_hash, CachePath, Expected, Found}) ->
-    io_lib:format("The checksum for package at ~s (~s) does not match the "
-                  "checksum previously locked (~s). Either unlock or "
+    io_lib:format("The checksum for package at ~ts (~ts) does not match the "
+                  "checksum previously locked (~ts). Either unlock or "
                   "upgrade the package, or make sure you fetched it from "
                   "the same index from which it was initially fetched.",
                   [CachePath, Found, Expected]);
 format_error({failed_extract, CachePath}) ->
-    io_lib:format("Failed to extract package: ~s", [CachePath]);
+    io_lib:format("Failed to extract package: ~ts", [CachePath]);
 format_error({bad_etag, Source}) ->
-    io_lib:format("MD5 Checksum comparison failed for: ~s", [Source]);
+    io_lib:format("MD5 Checksum comparison failed for: ~ts", [Source]);
 format_error({fetch_fail, Name, Vsn}) ->
-    io_lib:format("Failed to fetch and copy dep: ~s-~s", [Name, Vsn]);
+    io_lib:format("Failed to fetch and copy dep: ~ts-~ts", [Name, Vsn]);
 format_error({fetch_fail, Source}) ->
     io_lib:format("Failed to fetch and copy dep: ~p", [Source]);
 format_error({bad_checksum, File}) ->
-    io_lib:format("Checksum mismatch against tarball in ~s", [File]);
+    io_lib:format("Checksum mismatch against tarball in ~ts", [File]);
 format_error({bad_registry_checksum, File}) ->
-    io_lib:format("Checksum mismatch against registry in ~s", [File]).
+    io_lib:format("Checksum mismatch against registry in ~ts", [File]).
 
 get_resource_type({Type, Location}, Resources) ->
     find_resource_module(Type, Location, Resources);
@@ -100,7 +100,7 @@ find_resource_module(Type, Location, Resources) ->
         false ->
             case code:which(Type) of
                 non_existing ->
-                    {error, io_lib:format("Cannot handle dependency ~s.~n"
+                    {error, io_lib:format("Cannot handle dependency ~ts.~n"
                                          "     No module for resource type ~p", [Location, Type])};
                 _ ->
                     Type
diff --git a/src/rebar_file_utils.erl b/src/rebar_file_utils.erl
index 8158312..d7716e5 100644
--- a/src/rebar_file_utils.erl
+++ b/src/rebar_file_utils.erl
@@ -84,7 +84,7 @@ consult_config(State, Filename) ->
     [JoinedConfig].
 
 format_error({bad_term_file, AppFile, Reason}) ->
-    io_lib:format("Error reading file ~s: ~s", [AppFile, file:format_error(Reason)]).
+    io_lib:format("Error reading file ~ts: ~ts", [AppFile, file:format_error(Reason)]).
 
 symlink_or_copy(Source, Target) ->
     Link = case os:type() of
@@ -121,7 +121,7 @@ symlink_or_copy(Source, Target) ->
 
 win32_symlink(Source, Target) ->
     Res = rebar_utils:sh(
-            ?FMT("cmd /c mklink /j \"~s\" \"~s\"",
+            ?FMT("cmd /c mklink /j \"~ts\" \"~ts\"",
                  [rebar_utils:escape_double_quotes(filename:nativename(Target)),
                   rebar_utils:escape_double_quotes(filename:nativename(Source))]),
             [{use_stdout, false}, return_on_error]),
@@ -129,7 +129,7 @@ win32_symlink(Source, Target) ->
         true -> ok;
         false ->
             {error, lists:flatten(
-                      io_lib:format("Failed to symlink ~s to ~s~n",
+                      io_lib:format("Failed to symlink ~ts to ~ts~n",
                                     [Source, Target]))}
     end.
 
@@ -141,7 +141,7 @@ rm_rf(Target) ->
     case os:type() of
         {unix, _} ->
             EscTarget = rebar_utils:escape_chars(Target),
-            {ok, []} = rebar_utils:sh(?FMT("rm -rf ~s", [EscTarget]),
+            {ok, []} = rebar_utils:sh(?FMT("rm -rf ~ts", [EscTarget]),
                                       [{use_stdout, false}, abort_on_error]),
             ok;
         {win32, _} ->
@@ -161,7 +161,7 @@ cp_r(Sources, Dest) ->
         {unix, _} ->
             EscSources = [rebar_utils:escape_chars(Src) || Src <- Sources],
             SourceStr = string:join(EscSources, " "),
-            {ok, []} = rebar_utils:sh(?FMT("cp -Rp ~s \"~s\"",
+            {ok, []} = rebar_utils:sh(?FMT("cp -Rp ~ts \"~ts\"",
                                            [SourceStr, rebar_utils:escape_double_quotes(Dest)]),
                                       [{use_stdout, false}, abort_on_error]),
             ok;
@@ -176,7 +176,7 @@ mv(Source, Dest) ->
         {unix, _} ->
             EscSource = rebar_utils:escape_chars(Source),
             EscDest = rebar_utils:escape_chars(Dest),
-            case rebar_utils:sh(?FMT("mv ~s ~s", [EscSource, EscDest]),
+            case rebar_utils:sh(?FMT("mv ~ts ~ts", [EscSource, EscDest]),
                                       [{use_stdout, false}, abort_on_error]) of
                 {ok, []} ->
                     ok;
@@ -234,7 +234,7 @@ robocopy_mv_and_rename(Source, Dest, SrcDir, SrcName, DestDir, DestName) ->
     case ec_file:insecure_mkdtemp() of
         {error, _Reason} ->
             {error, lists:flatten(
-                     io_lib:format("Failed to move ~s to ~s (tmpdir failed)~n",
+                     io_lib:format("Failed to move ~ts to ~ts (tmpdir failed)~n",
                                    [Source, Dest]))};
         TmpPath ->
             case robocopy_file(SrcDir, TmpPath, SrcName) of
@@ -246,7 +246,7 @@ robocopy_mv_and_rename(Source, Dest, SrcDir, SrcName, DestDir, DestName) ->
                     case file:rename(TmpSrc, TmpDst) of
                         {error, _} ->
                             {error, lists:flatten(
-                                      io_lib:format("Failed to move ~s to ~s (via rename)~n",
+                                      io_lib:format("Failed to move ~ts to ~ts (via rename)~n",
                                                     [Source, Dest]))};
                         ok ->
                             case robocopy_file(TmpPath, DestDir, DestName) of
@@ -258,7 +258,7 @@ robocopy_mv_and_rename(Source, Dest, SrcDir, SrcName, DestDir, DestName) ->
     end.
 
 robocopy_file(SrcPath, DestPath, FileName) ->
-    Cmd = ?FMT("robocopy /move /e \"~s\" \"~s\" \"~s\"",
+    Cmd = ?FMT("robocopy /move /e \"~ts\" \"~ts\" \"~ts\"",
                [rebar_utils:escape_double_quotes(SrcPath),
                 rebar_utils:escape_double_quotes(DestPath),
                 rebar_utils:escape_double_quotes(FileName)]),
@@ -266,7 +266,7 @@ robocopy_file(SrcPath, DestPath, FileName) ->
     case win32_ok(Res) of
         false ->
             {error, lists:flatten(
-                        io_lib:format("Failed to move ~s to ~s~n",
+                        io_lib:format("Failed to move ~ts to ~ts~n",
                                       [filename:join(SrcPath, FileName),
                                        filename:join(DestPath, FileName)]))};
         true ->
@@ -274,7 +274,7 @@ robocopy_file(SrcPath, DestPath, FileName) ->
     end.
 
 robocopy_dir(Source, Dest) ->
-    Cmd = ?FMT("robocopy /move /e \"~s\" \"~s\"",
+    Cmd = ?FMT("robocopy /move /e \"~ts\" \"~ts\"",
                [rebar_utils:escape_double_quotes(Source),
                 rebar_utils:escape_double_quotes(Dest)]),
     Res = rebar_utils:sh(Cmd,
@@ -283,7 +283,7 @@ robocopy_dir(Source, Dest) ->
         true -> ok;
         false ->
             {error, lists:flatten(
-                      io_lib:format("Failed to move ~s to ~s~n",
+                      io_lib:format("Failed to move ~ts to ~ts~n",
                                     [Source, Dest]))}
     end.
 
@@ -301,12 +301,19 @@ delete_each([File | Rest]) ->
         {error, enoent} ->
             delete_each(Rest);
         {error, Reason} ->
-            ?ERROR("Failed to delete file ~s: ~p\n", [File, Reason]),
+            ?ERROR("Failed to delete file ~ts: ~p\n", [File, Reason]),
             ?FAIL
     end.
 
 write_file_if_contents_differ(Filename, Bytes) ->
-    ToWrite = iolist_to_binary(Bytes),
+    %% first try to convert directly to binaries,
+    %% but if it fails, we likely contain unicode and
+    %% need special treatment
+    ToWrite = try
+                  iolist_to_binary(Bytes)
+              catch
+                  error:badarg -> unicode:characters_to_binary(Bytes)
+              end,
     case file:read_file(Filename) of
         {ok, ToWrite} ->
             ok;
@@ -401,13 +408,13 @@ split_dirname(Path) ->
 
 delete_each_dir_win32([]) -> ok;
 delete_each_dir_win32([Dir | Rest]) ->
-    {ok, []} = rebar_utils:sh(?FMT("rd /q /s \"~s\"",
+    {ok, []} = rebar_utils:sh(?FMT("rd /q /s \"~ts\"",
                                    [rebar_utils:escape_double_quotes(filename:nativename(Dir))]),
                               [{use_stdout, false}, return_on_error]),
     delete_each_dir_win32(Rest).
 
 xcopy_win32(Source,Dest)->
-    %% "xcopy \"~s\" \"~s\" /q /y /e 2> nul", Changed to robocopy to
+    %% "xcopy \"~ts\" \"~ts\" /q /y /e 2> nul", Changed to robocopy to
     %% handle long names. May have issues with older windows.
     Cmd = case filelib:is_dir(Source) of
               true ->
@@ -417,11 +424,11 @@ xcopy_win32(Source,Dest)->
                   %% must manually add the last fragment of a directory to the `Dest`
                   %% in order to properly replicate POSIX platforms
                   NewDest = filename:join([Dest, filename:basename(Source)]),
-                  ?FMT("robocopy \"~s\" \"~s\" /e /is 1> nul",
+                  ?FMT("robocopy \"~ts\" \"~ts\" /e /is 1> nul",
                        [rebar_utils:escape_double_quotes(filename:nativename(Source)),
                         rebar_utils:escape_double_quotes(filename:nativename(NewDest))]);
               false ->
-                  ?FMT("robocopy \"~s\" \"~s\" \"~s\" /e /is 1> nul",
+                  ?FMT("robocopy \"~ts\" \"~ts\" \"~ts\" /e /is 1> nul",
                        [rebar_utils:escape_double_quotes(filename:nativename(filename:dirname(Source))),
                         rebar_utils:escape_double_quotes(filename:nativename(Dest)),
                         rebar_utils:escape_double_quotes(filename:basename(Source))])
@@ -432,7 +439,7 @@ xcopy_win32(Source,Dest)->
                 true -> ok;
                 false ->
                     {error, lists:flatten(
-                              io_lib:format("Failed to copy ~s to ~s~n",
+                              io_lib:format("Failed to copy ~ts to ~ts~n",
                                             [Source, Dest]))}
     end.
 
diff --git a/src/rebar_git_resource.erl b/src/rebar_git_resource.erl
index f666d17..a6b4d00 100644
--- a/src/rebar_git_resource.erl
+++ b/src/rebar_git_resource.erl
@@ -17,7 +17,7 @@
 lock(AppDir, {git, Url, _}) ->
     lock(AppDir, {git, Url});
 lock(AppDir, {git, Url}) ->
-    AbortMsg = lists:flatten(io_lib:format("Locking of git dependency failed in ~s", [AppDir])),
+    AbortMsg = lists:flatten(io_lib:format("Locking of git dependency failed in ~ts", [AppDir])),
     Dir = rebar_utils:escape_double_quotes(AppDir),
     {ok, VsnString} =
         case os:type() of
@@ -38,17 +38,17 @@ needs_update(Dir, {git, Url, {tag, Tag}}) ->
                                    [{cd, Dir}]),
     Current1 = string:strip(string:strip(Current, both, $\n), both, $\r),
 
-    ?DEBUG("Comparing git tag ~s with ~s", [Tag, Current1]),
+    ?DEBUG("Comparing git tag ~ts with ~ts", [Tag, Current1]),
     not ((Current1 =:= Tag) andalso compare_url(Dir, Url));
 needs_update(Dir, {git, Url, {branch, Branch}}) ->
     %% Fetch remote so we can check if the branch has changed
     SafeBranch = rebar_utils:escape_chars(Branch),
-    {ok, _} = rebar_utils:sh(?FMT("git fetch origin ~s", [SafeBranch]),
+    {ok, _} = rebar_utils:sh(?FMT("git fetch origin ~ts", [SafeBranch]),
                              [{cd, Dir}]),
     %% Check for new commits to origin/Branch
-    {ok, Current} = rebar_utils:sh(?FMT("git log HEAD..origin/~s --oneline", [SafeBranch]),
+    {ok, Current} = rebar_utils:sh(?FMT("git log HEAD..origin/~ts --oneline", [SafeBranch]),
                                    [{cd, Dir}]),
-    ?DEBUG("Checking git branch ~s for updates", [Branch]),
+    ?DEBUG("Checking git branch ~ts for updates", [Branch]),
     not ((Current =:= []) andalso compare_url(Dir, Url));
 needs_update(Dir, {git, Url, "master"}) ->
     needs_update(Dir, {git, Url, {branch, "master"}});
@@ -68,7 +68,7 @@ needs_update(Dir, {git, _, Ref}) ->
                    Ref
            end,
 
-    ?DEBUG("Comparing git ref ~s with ~s", [Ref2, Current1]),
+    ?DEBUG("Comparing git ref ~ts with ~ts", [Ref2, Current1]),
     (Current1 =/= Ref2).
 
 compare_url(Dir, Url) ->
@@ -82,7 +82,7 @@ compare_url(Dir, Url) ->
 
 parse_git_url(Url) ->
     %% Checks for standard scp style git remote
-    case re:run(Url, ?SCP_PATTERN, [{capture, [host, path], list}]) of
+    case re:run(Url, ?SCP_PATTERN, [{capture, [host, path], list}, unicode]) of
         {match, [Host, Path]} ->
             {ok, {Host, filename:rootname(Path, ".git")}};
         nomatch ->
@@ -119,41 +119,41 @@ download(Dir, {git, Url, Rev}, _State) ->
 
 %% Use different git clone commands depending on git --version
 git_clone(branch,Vsn,Url,Dir,Branch) when Vsn >= {1,7,10}; Vsn =:= undefined ->
-    rebar_utils:sh(?FMT("git clone ~s ~s -b ~s --single-branch",
+    rebar_utils:sh(?FMT("git clone ~ts ~ts -b ~ts --single-branch",
                         [rebar_utils:escape_chars(Url),
                          rebar_utils:escape_chars(filename:basename(Dir)),
                          rebar_utils:escape_chars(Branch)]),
                    [{cd, filename:dirname(Dir)}]);
 git_clone(branch,_Vsn,Url,Dir,Branch) ->
-    rebar_utils:sh(?FMT("git clone ~s ~s -b ~s",
+    rebar_utils:sh(?FMT("git clone ~ts ~ts -b ~ts",
                         [rebar_utils:escape_chars(Url),
                          rebar_utils:escape_chars(filename:basename(Dir)),
                          rebar_utils:escape_chars(Branch)]),
                    [{cd, filename:dirname(Dir)}]);
 git_clone(tag,Vsn,Url,Dir,Tag) when Vsn >= {1,7,10}; Vsn =:= undefined ->
-    rebar_utils:sh(?FMT("git clone ~s ~s -b ~s --single-branch",
+    rebar_utils:sh(?FMT("git clone ~ts ~ts -b ~ts --single-branch",
                         [rebar_utils:escape_chars(Url),
                          rebar_utils:escape_chars(filename:basename(Dir)),
                          rebar_utils:escape_chars(Tag)]),
                    [{cd, filename:dirname(Dir)}]);
 git_clone(tag,_Vsn,Url,Dir,Tag) ->
-    rebar_utils:sh(?FMT("git clone ~s ~s -b ~s",
+    rebar_utils:sh(?FMT("git clone ~ts ~ts -b ~ts",
                         [rebar_utils:escape_chars(Url),
                          rebar_utils:escape_chars(filename:basename(Dir)),
                          rebar_utils:escape_chars(Tag)]),
                    [{cd, filename:dirname(Dir)}]);
 git_clone(ref,_Vsn,Url,Dir,Ref) ->
-    rebar_utils:sh(?FMT("git clone -n ~s ~s",
+    rebar_utils:sh(?FMT("git clone -n ~ts ~ts",
                         [rebar_utils:escape_chars(Url),
                          rebar_utils:escape_chars(filename:basename(Dir))]),
                    [{cd, filename:dirname(Dir)}]),
-    rebar_utils:sh(?FMT("git checkout -q ~s", [Ref]), [{cd, Dir}]);
+    rebar_utils:sh(?FMT("git checkout -q ~ts", [Ref]), [{cd, Dir}]);
 git_clone(rev,_Vsn,Url,Dir,Rev) ->
-    rebar_utils:sh(?FMT("git clone -n ~s ~s",
+    rebar_utils:sh(?FMT("git clone -n ~ts ~ts",
                         [rebar_utils:escape_chars(Url),
                          rebar_utils:escape_chars(filename:basename(Dir))]),
                    [{cd, filename:dirname(Dir)}]),
-    rebar_utils:sh(?FMT("git checkout -q ~s", [rebar_utils:escape_chars(Rev)]),
+    rebar_utils:sh(?FMT("git checkout -q ~ts", [rebar_utils:escape_chars(Rev)]),
                    [{cd, Dir}]).
 
 git_vsn() ->
@@ -168,7 +168,7 @@ git_vsn() ->
 git_vsn_fetch() ->
     case rebar_utils:sh("git --version",[]) of
         {ok, VsnStr} ->
-            case re:run(VsnStr, "git version\\h+(\\d)\\.(\\d)\\.(\\d).*",[{capture,[1,2,3],list}]) of
+            case re:run(VsnStr, "git version\\h+(\\d)\\.(\\d)\\.(\\d).*", [{capture,[1,2,3],list}, unicode]) of
                 {match,[Maj,Min,Patch]} ->
                     {list_to_integer(Maj),
                      list_to_integer(Min),
@@ -198,7 +198,7 @@ collect_default_refcount(Dir) ->
                         return_on_error,
                         {cd, Dir}]) of
         {error, _} ->
-            ?WARN("Getting log of git dependency failed in ~s. Falling back to version 0.0.0", [rebar_dir:get_cwd()]),
+            ?WARN("Getting log of git dependency failed in ~ts. Falling back to version 0.0.0", [rebar_dir:get_cwd()]),
             {plain, "0.0.0"};
         {ok, String} ->
             RawRef = string:strip(String, both, $\n),
@@ -222,21 +222,20 @@ collect_default_refcount(Dir) ->
 build_vsn_string(Vsn, RawRef, Count) ->
     %% Cleanup the tag and the Ref information. Basically leading 'v's and
     %% whitespace needs to go away.
-    RefTag = [".ref", re:replace(RawRef, "\\s", "", [global])],
+    RefTag = [".ref", re:replace(RawRef, "\\s", "", [global, unicode])],
 
     %% Create the valid [semver](http://semver.org) version from the tag
     case Count of
         0 ->
-            erlang:binary_to_list(erlang:iolist_to_binary(Vsn));
+            rebar_utils:to_list(Vsn);
         _ ->
-            erlang:binary_to_list(erlang:iolist_to_binary([Vsn, "+build.",
-                                                           integer_to_list(Count), RefTag]))
+            rebar_utils:to_list([Vsn, "+build.", integer_to_list(Count), RefTag])
     end.
 
 get_patch_count(Dir, RawRef) ->
     AbortMsg = "Getting rev-list of git dep failed in " ++ Dir,
-    Ref = re:replace(RawRef, "\\s", "", [global]),
-    Cmd = io_lib:format("git rev-list ~s..HEAD",
+    Ref = re:replace(RawRef, "\\s", "", [global, unicode]),
+    Cmd = io_lib:format("git rev-list ~ts..HEAD",
                         [rebar_utils:escape_chars(Ref)]),
     {ok, PatchLines} = rebar_utils:sh(Cmd,
                                         [{use_stdout, false},
@@ -252,7 +251,7 @@ parse_tags(Dir) ->
         {error, _} ->
             {undefined, "0.0.0"};
         {ok, Line} ->
-            case re:run(Line, "(\\(|\\s)(HEAD[^,]*,\\s)tag:\\s(v?([^,\\)]+))", [{capture, [3, 4], list}]) of
+            case re:run(Line, "(\\(|\\s)(HEAD[^,]*,\\s)tag:\\s(v?([^,\\)]+))", [{capture, [3, 4], list}, unicode]) of
                 {match,[Tag, Vsn]} ->
                     {Tag, Vsn};
                 nomatch ->
diff --git a/src/rebar_hg_resource.erl b/src/rebar_hg_resource.erl
index 7d03eda..42e634c 100644
--- a/src/rebar_hg_resource.erl
+++ b/src/rebar_hg_resource.erl
@@ -22,7 +22,7 @@ lock(AppDir, {hg, Url}) ->
 needs_update(Dir, {hg, Url, {tag, Tag}}) ->
     Ref = get_ref(Dir),
     {ClosestTag, Distance} = get_tag_distance(Dir, Ref),
-    ?DEBUG("Comparing hg tag ~s with ref ~s (closest tag is ~s at distance ~s)",
+    ?DEBUG("Comparing hg tag ~ts with ref ~ts (closest tag is ~ts at distance ~ts)",
            [Tag, Ref, ClosestTag, Distance]),
     not ((Distance =:= "0") andalso (Tag =:= ClosestTag)
          andalso compare_url(Dir, Url));
@@ -45,7 +45,7 @@ needs_update(Dir, {hg, Url, Ref}) ->
         Ref1 ->
             Ref1
     end,
-    ?DEBUG("Comparing hg ref ~s with ~s", [Ref1, LocalRef]),
+    ?DEBUG("Comparing hg ref ~ts with ~ts", [Ref1, LocalRef]),
     not ((LocalRef =:= TargetRef) andalso compare_url(Dir, Url)).
 
 download(Dir, {hg, Url}, State) ->
@@ -56,28 +56,28 @@ download(Dir, {hg, Url, ""}, State) ->
     download(Dir, {hg, Url, {branch, "default"}}, State);
 download(Dir, {hg, Url, {branch, Branch}}, _State) ->
     ok = filelib:ensure_dir(Dir),
-    rebar_utils:sh(?FMT("hg clone -q -b ~s ~s ~s",
+    rebar_utils:sh(?FMT("hg clone -q -b ~ts ~ts ~ts",
                        [rebar_utils:escape_chars(Branch),
                         rebar_utils:escape_chars(Url),
                         rebar_utils:escape_chars(filename:basename(Dir))]),
                    [{cd, filename:dirname(Dir)}]);
 download(Dir, {hg, Url, {tag, Tag}}, _State) ->
     ok = filelib:ensure_dir(Dir),
-    rebar_utils:sh(?FMT("hg clone -q -u ~s ~s ~s",
+    rebar_utils:sh(?FMT("hg clone -q -u ~ts ~ts ~ts",
                         [rebar_utils:escape_chars(Tag),
                          rebar_utils:escape_chars(Url),
                          rebar_utils:escape_chars(filename:basename(Dir))]),
                    [{cd, filename:dirname(Dir)}]);
 download(Dir, {hg, Url, {ref, Ref}}, _State) ->
     ok = filelib:ensure_dir(Dir),
-    rebar_utils:sh(?FMT("hg clone -q -r ~s ~s ~s",
+    rebar_utils:sh(?FMT("hg clone -q -r ~ts ~ts ~ts",
                         [rebar_utils:escape_chars(Ref),
                          rebar_utils:escape_chars(Url),
                          rebar_utils:escape_chars(filename:basename(Dir))]),
                    [{cd, filename:dirname(Dir)}]);
 download(Dir, {hg, Url, Rev}, _State) ->
     ok = filelib:ensure_dir(Dir),
-    rebar_utils:sh(?FMT("hg clone -q -r ~s ~s ~s",
+    rebar_utils:sh(?FMT("hg clone -q -r ~ts ~ts ~ts",
                         [rebar_utils:escape_chars(Rev),
                          rebar_utils:escape_chars(Url),
                          rebar_utils:escape_chars(filename:basename(Dir))]),
@@ -88,7 +88,7 @@ make_vsn(Dir) ->
     Ref = get_ref(Dir),
     Cmd = BaseHg ++ "log --template \"{latesttag}+build.{latesttagdistance}.rev.{node|short}\""
           " --rev " ++ Ref,
-    AbortMsg = io_lib:format("Version resolution of hg dependency failed in ~s", [Dir]),
+    AbortMsg = io_lib:format("Version resolution of hg dependency failed in ~ts", [Dir]),
     {ok, VsnString} =
         rebar_utils:sh(Cmd,
                        [{use_stdout, false}, {debug_abort_on_error, AbortMsg}]),
@@ -108,14 +108,14 @@ compare_url(Dir, Url) ->
     parse_hg_url(CurrentUrl1) =:= parse_hg_url(Url).
 
 get_ref(Dir) ->
-    AbortMsg = io_lib:format("Get ref of hg dependency failed in ~s", [Dir]),
+    AbortMsg = io_lib:format("Get ref of hg dependency failed in ~ts", [Dir]),
     {ok, RefString} =
         rebar_utils:sh("hg -R \"" ++ rebar_utils:escape_double_quotes(Dir) ++ "\" --debug id -i",
                        [{use_stdout, false}, {debug_abort_on_error, AbortMsg}]),
     string:strip(RefString, both, $\n).
 
 get_tag_distance(Dir, Ref) ->
-    AbortMsg = io_lib:format("Get tag distance of hg dependency failed in ~s", [Dir]),
+    AbortMsg = io_lib:format("Get tag distance of hg dependency failed in ~ts", [Dir]),
     {ok, LogString} =
         rebar_utils:sh("hg -R \"" ++ rebar_utils:escape_double_quotes(Dir) ++ "\" "
                       "log --template \"{latesttag}-{latesttagdistance}\n\" "
@@ -123,11 +123,12 @@ get_tag_distance(Dir, Ref) ->
                       [{use_stdout, false}, {debug_abort_on_error, AbortMsg}]),
     Log = string:strip(LogString,
                        both, $\n),
-    [Tag, Distance] = re:split(Log, "-([0-9]+)$", [{parts,0}, {return, list}]),
+    [Tag, Distance] = re:split(Log, "-([0-9]+)$",
+                               [{parts,0}, {return,list}, unicode]),
     {Tag, Distance}.
 
 get_branch_ref(Dir, Branch) ->
-    AbortMsg = io_lib:format("Get branch ref of hg dependency failed in ~s", [Dir]),
+    AbortMsg = io_lib:format("Get branch ref of hg dependency failed in ~ts", [Dir]),
     {ok, BranchRefString} =
         rebar_utils:sh("hg -R \"" ++ rebar_utils:escape_double_quotes(Dir) ++
                        "\" log --template \"{node}\n\" --rev " ++ rebar_utils:escape_chars(Branch),
diff --git a/src/rebar_hooks.erl b/src/rebar_hooks.erl
index d6a0e2b..48aa928 100644
--- a/src/rebar_hooks.erl
+++ b/src/rebar_hooks.erl
@@ -57,9 +57,9 @@ run_provider_hooks_(Dir, Type, Command, Providers, TypeHooks, State) ->
     end.
 
 format_error({bad_provider, Type, Command, {Name, Namespace}}) ->
-    io_lib:format("Unable to run ~s hooks for '~p', command '~p' in namespace '~p' not found.", [Type, Command, Namespace, Name]);
+    io_lib:format("Unable to run ~ts hooks for '~p', command '~p' in namespace '~p' not found.", [Type, Command, Namespace, Name]);
 format_error({bad_provider, Type, Command, Name}) ->
-    io_lib:format("Unable to run ~s hooks for '~p', command '~p' not found.", [Type, Command, Name]).
+    io_lib:format("Unable to run ~ts hooks for '~p', command '~p' not found.", [Type, Command, Name]).
 
 %% @doc The following environment variables are exported when running
 %% a hook (absolute paths):
@@ -143,7 +143,7 @@ join_dirs(BaseDir, Dirs) ->
     string:join([ filename:join(BaseDir, Dir) || Dir <- Dirs ], ":").
 
 re_version(Path) ->
-    case re:run(Path, "^.*-(?<VER>[^/-]*)$", [{capture, [1], list}]) of
+    case re:run(Path, "^.*-(?<VER>[^/-]*)$", [{capture,[1],list}, unicode]) of
         nomatch -> "";
         {match, [Ver]} -> Ver
     end.
diff --git a/src/rebar_log.erl b/src/rebar_log.erl
index 47c84c5..9150346 100644
--- a/src/rebar_log.erl
+++ b/src/rebar_log.erl
@@ -94,7 +94,7 @@ get_level() ->
 
 log(Level = error, Str, Args) ->
     {ok, LogState} = application:get_env(rebar, log),
-    ec_cmd_log:Level(LogState, lists:flatten(cf:format("~!^~s~n", [Str])), Args);
+    ec_cmd_log:Level(LogState, lists:flatten(cf:format("~!^~ts~n", [Str])), Args);
 log(Level, Str, Args) ->
     {ok, LogState} = application:get_env(rebar, log),
     ec_cmd_log:Level(LogState, Str++"~n", Args).
diff --git a/src/rebar_otp_app.erl b/src/rebar_otp_app.erl
index ddaa44b..ed573f2 100644
--- a/src/rebar_otp_app.erl
+++ b/src/rebar_otp_app.erl
@@ -58,11 +58,11 @@ compile(State, App) ->
     validate_app(State, App1).
 
 format_error({missing_app_file, Filename}) ->
-    io_lib:format("App file is missing: ~s", [Filename]);
+    io_lib:format("App file is missing: ~ts", [Filename]);
 format_error({file_read, File, Reason}) ->
-    io_lib:format("Failed to read required file ~s for processing: ~s", [File, file:format_error(Reason)]);
+    io_lib:format("Failed to read required file ~ts for processing: ~ts", [File, file:format_error(Reason)]);
 format_error({invalid_name, File, AppName}) ->
-    io_lib:format("Invalid ~s: name of application (~p) must match filename.", [File, AppName]).
+    io_lib:format("Invalid ~ts: name of application (~p) must match filename.", [File, AppName]).
 
 %% ===================================================================
 %% Internal functions
@@ -222,7 +222,7 @@ app_vsn(AppData, AppFile, State) ->
 get_value(Key, AppInfo, AppFile) ->
     case proplists:get_value(Key, AppInfo) of
         undefined ->
-            ?ABORT("Failed to get app value '~p' from '~s'~n", [Key, AppFile]);
+            ?ABORT("Failed to get app value '~p' from '~ts'~n", [Key, AppFile]);
         Value ->
             Value
     end.
diff --git a/src/rebar_packages.erl b/src/rebar_packages.erl
index 5b6ab5c..cba1d16 100644
--- a/src/rebar_packages.erl
+++ b/src/rebar_packages.erl
@@ -72,12 +72,12 @@ deps(Name, Vsn, State) ->
 
 deps_(Name, Vsn, State) ->
     ?MODULE:verify_table(State),
-    ets:lookup_element(?PACKAGE_TABLE, {ec_cnv:to_binary(Name), ec_cnv:to_binary(Vsn)}, 2).
+    ets:lookup_element(?PACKAGE_TABLE, {rebar_utils:to_binary(Name), rebar_utils:to_binary(Vsn)}, 2).
 
 handle_missing_package(Dep, State, Fun) ->
     case Dep of
         {Name, Vsn} ->
-            ?INFO("Package ~s-~s not found. Fetching registry updates and trying again...", [Name, Vsn]);
+            ?INFO("Package ~ts-~ts not found. Fetching registry updates and trying again...", [Name, Vsn]);
         _ ->
             ?INFO("Package ~p not found. Fetching registry updates and trying again...", [Dep])
     end,
@@ -128,7 +128,7 @@ registry_checksum({pkg, Name, Vsn, _Hash}, State) ->
         ets:lookup_element(?PACKAGE_TABLE, {Name, Vsn}, 3)
     catch
         _:_ ->
-            throw(?PRV_ERROR({missing_package, ec_cnv:to_binary(Name), ec_cnv:to_binary(Vsn)}))
+            throw(?PRV_ERROR({missing_package, rebar_utils:to_binary(Name), rebar_utils:to_binary(Vsn)}))
     end.
 
 %% Hex supports use of ~> to specify the version required for a dependency.
@@ -207,17 +207,17 @@ handle_single_vsn(Pkg, PkgVsn, Dep, Vsn, Constraint) ->
         false ->
             case {Pkg, PkgVsn} of
                 {undefined, undefined} ->
-                    ?DEBUG("Only existing version of ~s is ~s which does not match constraint ~~> ~s. "
+                    ?DEBUG("Only existing version of ~ts is ~ts which does not match constraint ~~> ~ts. "
                           "Using anyway, but it is not guaranteed to work.", [Dep, Vsn, Constraint]);
                 _ ->
-                    ?DEBUG("[~s:~s] Only existing version of ~s is ~s which does not match constraint ~~> ~s. "
+                    ?DEBUG("[~ts:~ts] Only existing version of ~ts is ~ts which does not match constraint ~~> ~ts. "
                           "Using anyway, but it is not guaranteed to work.", [Pkg, PkgVsn, Dep, Vsn, Constraint])
             end,
             {ok, Vsn}
     end.
 
 format_error({missing_package, Name, Vsn}) ->
-    io_lib:format("Package not found in registry: ~s-~s.", [ec_cnv:to_binary(Name), ec_cnv:to_binary(Vsn)]);
+    io_lib:format("Package not found in registry: ~ts-~ts.", [rebar_utils:to_binary(Name), rebar_utils:to_binary(Vsn)]);
 format_error({missing_package, Dep}) ->
     io_lib:format("Package not found in registry: ~p.", [Dep]).
 
diff --git a/src/rebar_pkg_resource.erl b/src/rebar_pkg_resource.erl
index 88419bd..d588f24 100644
--- a/src/rebar_pkg_resource.erl
+++ b/src/rebar_pkg_resource.erl
@@ -21,7 +21,7 @@ lock(_AppDir, Source) ->
 
 needs_update(Dir, {pkg, _Name, Vsn, _Hash}) ->
     [AppInfo] = rebar_app_discover:find_apps([Dir], all),
-    case rebar_app_info:original_vsn(AppInfo) =:= ec_cnv:to_list(Vsn) of
+    case rebar_app_info:original_vsn(AppInfo) =:= rebar_utils:to_list(Vsn) of
         true ->
             false;
         false ->
@@ -43,13 +43,13 @@ download(TmpDir, Pkg={pkg, Name, Vsn, _Hash}, State) ->
 cached_download(TmpDir, CachePath, Pkg={pkg, Name, Vsn, _Hash}, Url, ETag, State) ->
     case request(Url, ETag) of
         {ok, cached} ->
-            ?INFO("Version cached at ~s is up to date, reusing it", [CachePath]),
+            ?INFO("Version cached at ~ts is up to date, reusing it", [CachePath]),
             serve_from_cache(TmpDir, CachePath, Pkg, State);
         {ok, Body, NewETag} ->
-            ?INFO("Downloaded package, caching at ~s", [CachePath]),
+            ?INFO("Downloaded package, caching at ~ts", [CachePath]),
             serve_from_download(TmpDir, CachePath, Pkg, NewETag, Body, State);
         error when ETag =/= false ->
-            ?INFO("Download error, using cached file at ~s", [CachePath]),
+            ?INFO("Download error, using cached file at ~ts", [CachePath]),
             serve_from_cache(TmpDir, CachePath, Pkg, State);
         error ->
             {fetch_fail, Name, Vsn}
@@ -76,13 +76,13 @@ serve_from_cache(TmpDir, CachePath, Pkg, State) ->
     end.
 
 serve_from_download(TmpDir, CachePath, Package, ETag, Binary, State) ->
-    ?DEBUG("Writing ~p to cache at ~s", [Package, CachePath]),
+    ?DEBUG("Writing ~p to cache at ~ts", [Package, CachePath]),
     file:write_file(CachePath, Binary),
     case etag(CachePath) of
         ETag ->
             serve_from_cache(TmpDir, CachePath, Package, State);
         FileETag ->
-            ?DEBUG("Downloaded file ~s ETag ~s doesn't match returned ETag ~s", [CachePath, ETag, FileETag]),
+            ?DEBUG("Downloaded file ~ts ETag ~ts doesn't match returned ETag ~ts", [CachePath, ETag, FileETag]),
             {bad_download, CachePath}
     end.
 
@@ -114,11 +114,11 @@ request(Url, ETag) ->
                        [{body_format, binary}],
                        rebar) of
         {ok, {{_Version, 200, _Reason}, Headers, Body}} ->
-            ?DEBUG("Successfully downloaded ~s", [Url]),
+            ?DEBUG("Successfully downloaded ~ts", [Url]),
             {"etag", ETag1} = lists:keyfind("etag", 1, Headers),
             {ok, Body, string:strip(ETag1, both, $")};
         {ok, {{_Version, 304, _Reason}, _Headers, _Body}} ->
-            ?DEBUG("Cached copy of ~s still valid", [Url]),
+            ?DEBUG("Cached copy of ~ts still valid", [Url]),
             {ok, cached};
         {ok, {{_Version, Code, _Reason}, _Headers, _Body}} ->
             ?DEBUG("Request to ~p failed: status code ~p", [Url, Code]),
@@ -154,7 +154,7 @@ ssl_opts(Url) ->
 ssl_opts(ssl_verify_enabled, Url) ->
     case check_ssl_version() of
         true ->
-            {ok, {_, _, Hostname, _, _, _}} = http_uri:parse(ec_cnv:to_list(Url)),
+            {ok, {_, _, Hostname, _, _, _}} = http_uri:parse(rebar_utils:to_list(Url)),
             VerifyFun = {fun ssl_verify_hostname:verify_fun/3, [{check_hostname, Hostname}]},
             CACerts = certifi:cacerts(),
             [{verify, verify_peer}, {depth, 2}, {cacerts, CACerts}
diff --git a/src/rebar_prv_app_discovery.erl b/src/rebar_prv_app_discovery.erl
index 1954214..3f10a3f 100644
--- a/src/rebar_prv_app_discovery.erl
+++ b/src/rebar_prv_app_discovery.erl
@@ -49,19 +49,19 @@ do(State) ->
 
 -spec format_error(any()) -> iolist().
 format_error({multiple_app_files, Files}) ->
-    io_lib:format("Multiple app files found in one app dir: ~s", [string:join(Files, " and ")]);
+    io_lib:format("Multiple app files found in one app dir: ~ts", [string:join(Files, " and ")]);
 format_error({invalid_app_file, File, Reason}) ->
     case Reason of
         {Line, erl_parse, Description} ->
-            io_lib:format("Invalid app file ~s at line ~b: ~p",
+            io_lib:format("Invalid app file ~ts at line ~b: ~p",
                 [File, Line, lists:flatten(Description)]);
         _ ->
-            io_lib:format("Invalid app file ~s: ~p", [File, Reason])
+            io_lib:format("Invalid app file ~ts: ~p", [File, Reason])
     end;
 %% Provide a slightly more informative error message for consult of app file failure
 format_error({rebar_file_utils, {bad_term_file, AppFile, Reason}}) ->
-    io_lib:format("Error in app file ~s: ~s", [rebar_dir:make_relative_path(AppFile,
-                                                                            rebar_dir:get_cwd()),
-                                               file:format_error(Reason)]);
+    io_lib:format("Error in app file ~ts: ~ts", [rebar_dir:make_relative_path(AppFile,
+                                                                              rebar_dir:get_cwd()),
+                                                 file:format_error(Reason)]);
 format_error(Reason) ->
     io_lib:format("~p", [Reason]).
diff --git a/src/rebar_prv_as.erl b/src/rebar_prv_as.erl
index e7c6d68..562ce99 100644
--- a/src/rebar_prv_as.erl
+++ b/src/rebar_prv_as.erl
@@ -64,7 +64,7 @@ args_to_profiles_and_tasks(Args) ->
 
 first_profile([]) -> {[], []};
 first_profile([ProfileList|Rest]) ->
-    case re:split(ProfileList, ",", [{return, list}, {parts, 2}]) of
+    case re:split(ProfileList, ",", [{return, list}, {parts, 2}, unicode]) of
         %% `foo, bar`
         [P, ""]   -> profiles(Rest, [P]);
         %% `foo,bar`
@@ -75,7 +75,7 @@ first_profile([ProfileList|Rest]) ->
 
 profiles([], Acc) -> {lists:reverse(Acc), rebar_utils:args_to_tasks([])};
 profiles([ProfileList|Rest], Acc) ->
-    case re:split(ProfileList, ",", [{return, list}, {parts, 2}]) of
+    case re:split(ProfileList, ",", [{return, list}, {parts, 2}, unicode]) of
         %% `foo, bar`
         [P, ""]   -> profiles(Rest, [P|Acc]);
         %% `foo,bar`
@@ -101,5 +101,5 @@ warn_on_empty_profile(Profiles, State) ->
     ProjectApps = rebar_state:project_apps(State),
     DefinedProfiles = rebar_state:get(State, profiles, []) ++
         lists:flatten([rebar_app_info:get(AppInfo, profiles, []) || AppInfo <- ProjectApps]),
-    [?WARN("No entry for profile ~s in config.", [Profile]) ||
+    [?WARN("No entry for profile ~ts in config.", [Profile]) ||
         Profile <- Profiles, not(lists:keymember(list_to_atom(Profile), 1, DefinedProfiles))].
diff --git a/src/rebar_prv_clean.erl b/src/rebar_prv_clean.erl
index d185f75..aa0b5af 100644
--- a/src/rebar_prv_clean.erl
+++ b/src/rebar_prv_clean.erl
@@ -68,7 +68,7 @@ format_error(Reason) ->
 
 clean_apps(State, Providers, Apps) ->
     [begin
-         ?INFO("Cleaning out ~s...", [rebar_app_info:name(AppInfo)]),
+         ?INFO("Cleaning out ~ts...", [rebar_app_info:name(AppInfo)]),
          AppDir = rebar_app_info:dir(AppInfo),
          AppInfo1 = rebar_hooks:run_all_hooks(AppDir, pre, ?PROVIDER, Providers, AppInfo, State),
          rebar_erlc_compiler:clean(AppInfo1),
diff --git a/src/rebar_prv_common_test.erl b/src/rebar_prv_common_test.erl
index dfade77..bf788d2 100644
--- a/src/rebar_prv_common_test.erl
+++ b/src/rebar_prv_common_test.erl
@@ -684,7 +684,7 @@ format_result({Passed, 0, {0, 0}}) ->
 format_result({Passed, Failed, Skipped}) ->
     Format = [format_failed(Failed), format_skipped(Skipped),
               format_passed(Passed)],
-    ?CONSOLE("~s", [Format]);
+    ?CONSOLE("~ts", [Format]);
 format_result(_Unknown) ->
     %% Happens when CT itself encounters a bug
     ok.
diff --git a/src/rebar_prv_compile.erl b/src/rebar_prv_compile.erl
index effc763..959ecb0 100644
--- a/src/rebar_prv_compile.erl
+++ b/src/rebar_prv_compile.erl
@@ -73,7 +73,7 @@ do(State) ->
 
 -spec format_error(any()) -> iolist().
 format_error({missing_artifact, File}) ->
-    io_lib:format("Missing artifact ~s", [File]);
+    io_lib:format("Missing artifact ~ts", [File]);
 format_error(Reason) ->
     io_lib:format("~p", [Reason]).
 
@@ -114,7 +114,7 @@ compile(State, AppInfo) ->
     compile(State, rebar_state:providers(State), AppInfo).
 
 compile(State, Providers, AppInfo) ->
-    ?INFO("Compiling ~s", [rebar_app_info:name(AppInfo)]),
+    ?INFO("Compiling ~ts", [rebar_app_info:name(AppInfo)]),
     AppDir = rebar_app_info:dir(AppInfo),
     AppInfo1 = rebar_hooks:run_all_hooks(AppDir, pre, ?PROVIDER,  Providers, AppInfo, State),
 
@@ -173,8 +173,8 @@ has_all_artifacts(AppInfo1) ->
     end.
 
 copy_app_dirs(AppInfo, OldAppDir, AppDir) ->
-    case ec_cnv:to_binary(filename:absname(OldAppDir)) =/=
-        ec_cnv:to_binary(filename:absname(AppDir)) of
+    case rebar_utils:to_binary(filename:absname(OldAppDir)) =/=
+        rebar_utils:to_binary(filename:absname(AppDir)) of
         true ->
             EbinDir = filename:join([OldAppDir, "ebin"]),
             %% copy all files from ebin if it exists
diff --git a/src/rebar_prv_cover.erl b/src/rebar_prv_cover.erl
index bf142c4..fca7c40 100644
--- a/src/rebar_prv_cover.erl
+++ b/src/rebar_prv_cover.erl
@@ -278,7 +278,7 @@ write_index(State, Coverage) ->
 write_index_section(_F, []) -> ok;
 write_index_section(F, [{Section, DataFile, Mods}|Rest]) ->
     %% Write the report
-    ok = file:write(F, ?FMT("<h1>~s summary</h1>\n", [Section])),
+    ok = file:write(F, ?FMT("<h1>~ts summary</h1>\n", [Section])),
     ok = file:write(F, "coverage calculated from:\n<ul>"),
     ok = lists:foreach(fun(D) -> ok = file:write(F, io_lib:format("<li>~ts</li>", [D])) end,
                        DataFile),
@@ -303,7 +303,7 @@ strip_coverdir(File) ->
                                               2))).
 
 cover_compile(State, apps) ->
-    ExclApps = [list_to_binary(A) || A <- rebar_state:get(State, cover_excl_apps, [])],
+    ExclApps = [rebar_utils:to_binary(A) || A <- rebar_state:get(State, cover_excl_apps, [])],
     Apps = filter_checkouts_and_excluded(rebar_state:project_apps(State), ExclApps),
     AppDirs = app_dirs(Apps),
     cover_compile(State, lists:filter(fun(D) -> ec_file:is_dir(D) end, AppDirs));
diff --git a/src/rebar_prv_deps.erl b/src/rebar_prv_deps.erl
index 9ff2bfa..a88b014 100644
--- a/src/rebar_prv_deps.erl
+++ b/src/rebar_prv_deps.erl
@@ -55,7 +55,7 @@ merge(Deps, SourceDeps) ->
 normalize(Name) when is_binary(Name) ->
     Name;
 normalize(Name) when is_atom(Name) ->
-    ec_cnv:to_binary(Name);
+    atom_to_binary(Name, unicode);
 normalize(Dep) when is_tuple(Dep) ->
     Name = element(1, Dep),
     setelement(1, Dep, normalize(Name)).
@@ -87,31 +87,31 @@ display_deps(State, Deps) ->
 
 %% packages
 display_dep(_State, {Name, Vsn}) when is_list(Vsn) ->
-    ?CONSOLE("~s* (package ~s)", [ec_cnv:to_binary(Name), ec_cnv:to_binary(Vsn)]);
+    ?CONSOLE("~ts* (package ~ts)", [rebar_utils:to_binary(Name), rebar_utils:to_binary(Vsn)]);
 display_dep(_State, Name) when is_binary(Name) ->
-    ?CONSOLE("~s* (package)", [Name]);
+    ?CONSOLE("~ts* (package)", [Name]);
 display_dep(_State, {Name, Source}) when is_tuple(Source) ->
-    ?CONSOLE("~s* (~s source)", [ec_cnv:to_binary(Name), type(Source)]);
+    ?CONSOLE("~ts* (~ts source)", [rebar_utils:to_binary(Name), type(Source)]);
 display_dep(_State, {Name, _Vsn, Source}) when is_tuple(Source) ->
-    ?CONSOLE("~s* (~s source)", [ec_cnv:to_binary(Name), type(Source)]);
+    ?CONSOLE("~ts* (~ts source)", [rebar_utils:to_binary(Name), type(Source)]);
 display_dep(_State, {Name, _Vsn, Source, _Opts}) when is_tuple(Source) ->
-    ?CONSOLE("~s* (~s source)", [ec_cnv:to_binary(Name), type(Source)]);
+    ?CONSOLE("~ts* (~ts source)", [rebar_utils:to_binary(Name), type(Source)]);
 %% Locked
 display_dep(State, {Name, Source={pkg, _, Vsn}, Level}) when is_integer(Level) ->
     DepsDir = rebar_dir:deps_dir(State),
-    AppDir = filename:join([DepsDir, ec_cnv:to_binary(Name)]),
+    AppDir = filename:join([DepsDir, rebar_utils:to_binary(Name)]),
     NeedsUpdate = case rebar_fetch:needs_update(AppDir, Source, State) of
         true -> "*";
         false -> ""
     end,
-    ?CONSOLE("~s~s (locked package ~s)", [Name, NeedsUpdate, Vsn]);
+    ?CONSOLE("~ts~ts (locked package ~ts)", [Name, NeedsUpdate, Vsn]);
 display_dep(State, {Name, Source, Level}) when is_tuple(Source), is_integer(Level) ->
     DepsDir = rebar_dir:deps_dir(State),
-    AppDir = filename:join([DepsDir, ec_cnv:to_binary(Name)]),
+    AppDir = filename:join([DepsDir, rebar_utils:to_binary(Name)]),
     NeedsUpdate = case rebar_fetch:needs_update(AppDir, Source, State) of
         true -> "*";
         false -> ""
     end,
-    ?CONSOLE("~s~s (locked ~s source)", [Name, NeedsUpdate, type(Source)]).
+    ?CONSOLE("~ts~ts (locked ~ts source)", [Name, NeedsUpdate, type(Source)]).
 
 type(Source) when is_tuple(Source) -> element(1, Source).
diff --git a/src/rebar_prv_deps_tree.erl b/src/rebar_prv_deps_tree.erl
index c0c8bab..7c6978b 100644
--- a/src/rebar_prv_deps_tree.erl
+++ b/src/rebar_prv_deps_tree.erl
@@ -90,7 +90,7 @@ type(Source, Verbose) when is_tuple(Source) ->
         {pkg, _} ->
             "hex package";
         {Other, false} ->
-            io_lib:format("~s repo", [Other]);
+            io_lib:format("~ts repo", [Other]);
         {_, true} ->
-            io_lib:format("~s", [element(2, Source)])
+            io_lib:format("~ts", [element(2, Source)])
     end.
diff --git a/src/rebar_prv_dialyzer.erl b/src/rebar_prv_dialyzer.erl
index 867b9cb..a74eefb 100644
--- a/src/rebar_prv_dialyzer.erl
+++ b/src/rebar_prv_dialyzer.erl
@@ -116,18 +116,18 @@ maybe_fix_env() ->
 
 -spec format_error(any()) -> iolist().
 format_error({error_processing_apps, Error}) ->
-    io_lib:format("Error in dialyzing apps: ~s", [Error]);
+    io_lib:format("Error in dialyzing apps: ~ts", [Error]);
 format_error({dialyzer_warnings, Warnings}) ->
     io_lib:format("Warnings occurred running dialyzer: ~b", [Warnings]);
 format_error({unknown_application, App}) ->
-    io_lib:format("Could not find application: ~s", [App]);
+    io_lib:format("Could not find application: ~ts", [App]);
 format_error({unknown_module, Mod}) ->
-    io_lib:format("Could not find module: ~s", [Mod]);
+    io_lib:format("Could not find module: ~ts", [Mod]);
 format_error({duplicate_module, Mod, File1, File2}) ->
-    io_lib:format("Duplicates of module ~s: ~s ~s", [Mod, File1, File2]);
+    io_lib:format("Duplicates of module ~ts: ~ts ~ts", [Mod, File1, File2]);
 format_error({output_file_error, File, Error}) ->
     Error1 = file:format_error(Error),
-    io_lib:format("Failed to write to ~s: ~s", [File, Error1]);
+    io_lib:format("Failed to write to ~ts: ~ts", [File, Error1]);
 format_error(Reason) ->
     io_lib:format("~p", [Reason]).
 
@@ -155,7 +155,7 @@ do(State, Plt) ->
         0 ->
             {ok, State2};
         TotalWarnings ->
-            ?INFO("Warnings written to ~s", [Output]),
+            ?INFO("Warnings written to ~ts", [Output]),
             throw({dialyzer_warnings, TotalWarnings})
     end.
 
@@ -229,7 +229,7 @@ apps_files([AppName | DepApps], SkipApps, Files) ->
             apps_files(DepApps, SkipApps, Files);
         false ->
             AppFiles = app_files(AppName),
-            ?DEBUG("~s modules: ~p", [AppName, dict:fetch_keys(AppFiles)]),
+            ?DEBUG("~ts modules: ~p", [AppName, dict:fetch_keys(AppFiles)]),
             Files2 = merge_files(Files, AppFiles),
             apps_files(DepApps, [AppName | SkipApps], Files2)
     end.
@@ -505,7 +505,7 @@ format_warnings(Opts, Output, Warnings) ->
     length(Warnings).
 
 console_warnings(Warnings) ->
-    _ = [?CONSOLE("~s", [Warning]) || Warning <- Warnings],
+    _ = [?CONSOLE("~ts", [Warning]) || Warning <- Warnings],
     ok.
 
 file_warnings(_, []) ->
diff --git a/src/rebar_prv_edoc.erl b/src/rebar_prv_edoc.erl
index d663b0c..9517335 100644
--- a/src/rebar_prv_edoc.erl
+++ b/src/rebar_prv_edoc.erl
@@ -42,8 +42,8 @@ do(State) ->
     Res = try
         lists:foldl(fun(AppInfo, EdocOptsAcc) ->
                     rebar_hooks:run_all_hooks(Cwd, pre, ?PROVIDER, Providers, AppInfo, State),
-                    AppName = ec_cnv:to_list(rebar_app_info:name(AppInfo)),
-                    ?INFO("Running edoc for ~s", [AppName]),
+                    AppName = rebar_utils:to_list(rebar_app_info:name(AppInfo)),
+                    ?INFO("Running edoc for ~ts", [AppName]),
                     AppDir = rebar_app_info:dir(AppInfo),
                     AppRes = (catch edoc:application(list_to_atom(AppName), AppDir, EdocOptsAcc)),
                     rebar_hooks:run_all_hooks(Cwd, post, ?PROVIDER, Providers, AppInfo, State),
@@ -74,7 +74,7 @@ do(State) ->
 
 -spec format_error(any()) -> iolist().
 format_error({app_failed, AppName}) ->
-    io_lib:format("Failed to generate documentation for app '~s'", [AppName]);
+    io_lib:format("Failed to generate documentation for app '~ts'", [AppName]);
 format_error(Reason) ->
     io_lib:format("~p", [Reason]).
 
diff --git a/src/rebar_prv_escriptize.erl b/src/rebar_prv_escriptize.erl
index 56b0d8a..cffbbdc 100644
--- a/src/rebar_prv_escriptize.erl
+++ b/src/rebar_prv_escriptize.erl
@@ -75,7 +75,7 @@ do(State) ->
             end;
         Name ->
             AllApps = rebar_state:all_deps(State)++rebar_state:project_apps(State),
-            case rebar_app_utils:find(ec_cnv:to_binary(Name), AllApps) of
+            case rebar_app_utils:find(rebar_utils:to_binary(Name), AllApps) of
                 {ok, AppInfo} ->
                     escriptize(State, AppInfo);
                 _ ->
@@ -87,12 +87,12 @@ do(State) ->
 
 escriptize(State0, App) ->
     AppName = rebar_app_info:name(App),
-    AppNameStr = ec_cnv:to_list(AppName),
+    AppNameStr = rebar_utils:to_list(AppName),
 
     %% Get the output filename for the escript -- this may include dirs
     Filename = filename:join([rebar_dir:base_dir(State0), "bin",
                               rebar_state:get(State0, escript_name, AppName)]),
-    ?DEBUG("Creating escript file ~s", [Filename]),
+    ?DEBUG("Creating escript file ~ts", [Filename]),
     ok = filelib:ensure_dir(Filename),
     State = rebar_state:escript_path(State0, Filename),
 
@@ -116,7 +116,7 @@ escriptize(State0, App) ->
     ExtraFiles = usort(InclBeams ++ InclExtra),
     Files = get_nonempty(EbinFiles ++ ExtraFiles),
 
-    DefaultEmuArgs = ?FMT("%%! -escript main ~s -pz ~s/~s/ebin\n",
+    DefaultEmuArgs = ?FMT("%%! -escript main ~ts -pz ~ts/~ts/ebin\n",
                           [AppNameStr, AppNameStr, AppNameStr]),
     EscriptSections =
         [ {shebang,
@@ -163,7 +163,7 @@ get_apps_beams(Apps, AllApps) ->
 get_apps_beams([], _, Acc) ->
     Acc;
 get_apps_beams([App | Rest], AllApps, Acc) ->
-    case rebar_app_utils:find(ec_cnv:to_binary(App), AllApps) of
+    case rebar_app_utils:find(rebar_utils:to_binary(App), AllApps) of
         {ok, App1} ->
             OutDir = filename:absname(rebar_app_info:ebin_dir(App1)),
             Beams = get_app_beams(App, OutDir),
@@ -235,7 +235,7 @@ get_nonempty(Files) ->
     [{FName,FBin} || {FName,FBin} <- Files, FBin =/= <<>>].
 
 find_deps(AppNames, AllApps) ->
-    BinAppNames = [ec_cnv:to_binary(Name) || Name <- AppNames],
+    BinAppNames = [rebar_utils:to_binary(Name) || Name <- AppNames],
     [ec_cnv:to_atom(Name) ||
      Name <- find_deps_of_deps(BinAppNames, AllApps, BinAppNames)].
 
@@ -245,7 +245,7 @@ find_deps_of_deps([Name|Names], Apps, Acc) ->
     ?DEBUG("processing ~p", [Name]),
     {ok, App} = rebar_app_utils:find(Name, Apps),
     DepNames = proplists:get_value(applications, rebar_app_info:app_details(App), []),
-    BinDepNames = [ec_cnv:to_binary(Dep) || Dep <- DepNames,
+    BinDepNames = [rebar_utils:to_binary(Dep) || Dep <- DepNames,
                    %% ignore system libs; shouldn't include them.
                    DepDir <- [code:lib_dir(Dep)],
                    DepDir =:= {error, bad_name} orelse % those are all local
diff --git a/src/rebar_prv_install_deps.erl b/src/rebar_prv_install_deps.erl
index c9fe0ad..55dca3d 100644
--- a/src/rebar_prv_install_deps.erl
+++ b/src/rebar_prv_install_deps.erl
@@ -104,22 +104,22 @@ do_(State) ->
 %% @doc convert a given exception's payload into an io description.
 -spec format_error(any()) -> iolist().
 format_error({dep_app_not_found, AppDir, AppName}) ->
-    io_lib:format("Dependency failure: Application ~s not found at the top level of directory ~s", [AppName, AppDir]);
+    io_lib:format("Dependency failure: Application ~ts not found at the top level of directory ~ts", [AppName, AppDir]);
 format_error({load_registry_fail, Dep}) ->
-    io_lib:format("Error loading registry to resolve version of ~s. Try fixing by running 'rebar3 update'", [Dep]);
+    io_lib:format("Error loading registry to resolve version of ~ts. Try fixing by running 'rebar3 update'", [Dep]);
 format_error({bad_constraint, Name, Constraint}) ->
-    io_lib:format("Unable to parse version for package ~s: ~s", [Name, Constraint]);
+    io_lib:format("Unable to parse version for package ~ts: ~ts", [Name, Constraint]);
 format_error({parse_dep, Dep}) ->
     io_lib:format("Failed parsing dep ~p", [Dep]);
 format_error({not_rebar_package, Package, Version}) ->
-    io_lib:format("Package not buildable with rebar3: ~s-~s", [Package, Version]);
+    io_lib:format("Package not buildable with rebar3: ~ts-~ts", [Package, Version]);
 format_error({missing_package, Package, Version}) ->
-    io_lib:format("Package not found in registry: ~s-~s", [Package, Version]);
+    io_lib:format("Package not found in registry: ~ts-~ts", [Package, Version]);
 format_error({missing_package, Package}) ->
-    io_lib:format("Package not found in registry: ~s", [Package]);
+    io_lib:format("Package not found in registry: ~ts", [Package]);
 format_error({cycles, Cycles}) ->
     Prints = [["applications: ",
-               [io_lib:format("~s ", [Dep]) || Dep <- Cycle],
+               [io_lib:format("~ts ", [Dep]) || Dep <- Cycle],
                "depend on each other\n"]
               || Cycle <- Cycles],
     ["Dependency cycle(s) detected:\n", Prints];
@@ -291,7 +291,7 @@ handle_dep(State, Profile, DepsDir, AppInfo, Locks, Level) ->
 -spec maybe_fetch(rebar_app_info:t(), atom(), boolean(),
                   sets:set(binary()), rebar_state:t()) -> {boolean(), rebar_app_info:t()}.
 maybe_fetch(AppInfo, Profile, Upgrade, Seen, State) ->
-    AppDir = ec_cnv:to_list(rebar_app_info:dir(AppInfo)),
+    AppDir = rebar_utils:to_list(rebar_app_info:dir(AppInfo)),
     %% Don't fetch dep if it exists in the _checkouts dir
     case rebar_app_info:is_checkout(AppInfo) of
         true ->
@@ -346,7 +346,7 @@ symlink_dep(State, From, To) ->
         ok ->
             RelativeFrom = make_relative_to_root(State, From),
             RelativeTo = make_relative_to_root(State, To),
-            ?INFO("Linking ~s to ~s", [RelativeFrom, RelativeTo]),
+            ?INFO("Linking ~ts to ~ts", [RelativeFrom, RelativeTo]),
             ok;
         exists ->
             ok
@@ -359,7 +359,7 @@ make_relative_to_root(State, Path) when is_list(Path) ->
     rebar_dir:make_relative_path(Path, Root).
 
 fetch_app(AppInfo, AppDir, State) ->
-    ?INFO("Fetching ~s (~p)", [rebar_app_info:name(AppInfo),
+    ?INFO("Fetching ~ts (~p)", [rebar_app_info:name(AppInfo),
                                format_source(rebar_app_info:source(AppInfo))]),
     Source = rebar_app_info:source(AppInfo),
     true = rebar_fetch:download_source(AppDir, Source, State).
@@ -384,12 +384,12 @@ maybe_upgrade(AppInfo, AppDir, Upgrade, State) ->
         true ->
             case rebar_fetch:needs_update(AppDir, Source, State) of
                 true ->
-                    ?INFO("Upgrading ~s (~p)", [rebar_app_info:name(AppInfo), rebar_app_info:source(AppInfo)]),
+                    ?INFO("Upgrading ~ts (~p)", [rebar_app_info:name(AppInfo), rebar_app_info:source(AppInfo)]),
                     true = rebar_fetch:download_source(AppDir, Source, State);
                 false ->
                     case Upgrade of
                         true ->
-                            ?INFO("No upgrade needed for ~s", [rebar_app_info:name(AppInfo)]),
+                            ?INFO("No upgrade needed for ~ts", [rebar_app_info:name(AppInfo)]),
                             false;
                         false ->
                             false
@@ -400,7 +400,7 @@ maybe_upgrade(AppInfo, AppDir, Upgrade, State) ->
     end.
 
 warn_skip_deps(AppInfo, State) ->
-    Msg = "Skipping ~s (from ~p) as an app of the same name "
+    Msg = "Skipping ~ts (from ~p) as an app of the same name "
           "has already been fetched",
     Args = [rebar_app_info:name(AppInfo),
             rebar_app_info:source(AppInfo)],
diff --git a/src/rebar_prv_local_install.erl b/src/rebar_prv_local_install.erl
index 0b30fd4..282c548 100644
--- a/src/rebar_prv_local_install.erl
+++ b/src/rebar_prv_local_install.erl
@@ -60,7 +60,7 @@ format_error(Reason) ->
 bin_contents(OutputDir) ->
     <<"#!/usr/bin/env sh
 
-erl -pz ", (ec_cnv:to_binary(OutputDir))/binary,"/*/ebin +sbtu +A0 -noshell -boot start_clean -s rebar3 main $REBAR3_ERL_ARGS -extra \"$@\"
+erl -pz ", (rebar_utils:to_binary(OutputDir))/binary,"/*/ebin +sbtu +A0 -noshell -boot start_clean -s rebar3 main $REBAR3_ERL_ARGS -extra \"$@\"
 ">>.
 
 extract_escript(State, ScriptPath) ->
@@ -73,7 +73,7 @@ extract_escript(State, ScriptPath) ->
     OutputDir = filename:join(rebar_dir:global_cache_dir(Opts), "lib"),
     filelib:ensure_dir(filename:join(OutputDir, "empty")),
 
-    ?INFO("Extracting rebar3 libs to ~s...", [OutputDir]),
+    ?INFO("Extracting rebar3 libs to ~ts...", [OutputDir]),
     zip:extract(Archive, [{cwd, OutputDir}]),
 
     BinDir = filename:join(rebar_dir:global_cache_dir(Opts), "bin"),
@@ -84,12 +84,12 @@ extract_escript(State, ScriptPath) ->
                     uid = Uid,
                     gid = Gid}} = file:read_file_info(ScriptPath),
 
-    ?INFO("Writing rebar3 run script ~s...", [BinFile]),
+    ?INFO("Writing rebar3 run script ~ts...", [BinFile]),
     file:write_file(BinFile, bin_contents(OutputDir)),
     ok = file:write_file_info(BinFile, #file_info{mode=33277,
                                                   uid=Uid,
                                                   gid=Gid}),
 
-    ?INFO("Add to $PATH for use: export PATH=~s:$PATH", [BinDir]),
+    ?INFO("Add to $PATH for use: export PATH=~ts:$PATH", [BinDir]),
 
     {ok, State}.
diff --git a/src/rebar_prv_new.erl b/src/rebar_prv_new.erl
index 152a56e..f632362 100644
--- a/src/rebar_prv_new.erl
+++ b/src/rebar_prv_new.erl
@@ -60,7 +60,7 @@ do(State) ->
 
 -spec format_error(any()) -> iolist().
 format_error({consult, File, Reason}) ->
-    io_lib:format("Error consulting file at ~s for reason ~p", [File, Reason]);
+    io_lib:format("Error consulting file at ~ts for reason ~p", [File, Reason]);
 format_error(Reason) ->
     io_lib:format("~p", [Reason]).
 
@@ -70,7 +70,7 @@ format_error(Reason) ->
 
 list_templates(State) ->
     lists:foldl(fun({error, {consult, File, Reason}}, Acc) ->
-                    ?WARN("Error consulting template file ~s for reason ~p",
+                    ?WARN("Error consulting template file ~ts for reason ~p",
                           [File, Reason]),
                     Acc
                 ;  (Tpl, Acc) ->
@@ -116,16 +116,16 @@ show_short_templates(List) ->
     lists:map(fun show_short_template/1, lists:sort(List)).
 
 show_short_template({Name, Type, _Location, Description, _Vars}) ->
-    io:format("~s (~s): ~s~n",
+    io:format("~ts (~ts): ~ts~n",
               [Name,
                format_type(Type),
                format_description(Description)]).
 
 show_template({Name, Type, Location, Description, Vars}) ->
-    io:format("~s:~n"
-              "\t~s~n"
-              "\tDescription: ~s~n"
-              "\tVariables:~n~s~n",
+    io:format("~ts:~n"
+              "\t~ts~n"
+              "\tDescription: ~ts~n"
+              "\tVariables:~n~ts~n",
               [Name,
                format_type(Type, Location),
                format_description(Description),
@@ -141,9 +141,9 @@ format_type(escript, _) ->
 format_type(builtin, _) ->
     "built-in template";
 format_type(plugin, Loc) ->
-    io_lib:format("plugin template (~s)", [Loc]);
+    io_lib:format("plugin template (~ts)", [Loc]);
 format_type(file, Loc) ->
-    io_lib:format("custom template (~s)", [Loc]).
+    io_lib:format("custom template (~ts)", [Loc]).
 
 format_description(Description) ->
     case Description of
@@ -156,4 +156,4 @@ format_vars(Vars) -> [format_var(Var) || Var <- Vars].
 format_var({Var, Default}) ->
     io_lib:format("\t\t~p=~p~n",[Var, Default]);
 format_var({Var, Default, Doc}) ->
-    io_lib:format("\t\t~p=~p (~s)~n", [Var, Default, Doc]).
+    io_lib:format("\t\t~p=~p (~ts)~n", [Var, Default, Doc]).
diff --git a/src/rebar_prv_packages.erl b/src/rebar_prv_packages.erl
index 7217ab8..6e8e683 100644
--- a/src/rebar_prv_packages.erl
+++ b/src/rebar_prv_packages.erl
@@ -30,7 +30,7 @@ do(State) ->
     rebar_packages:packages(State),
     case rebar_state:command_args(State) of
         [Name] ->
-            print_packages(get_packages(iolist_to_binary(Name)));
+            print_packages(get_packages(rebar_utils:to_binary(Name)));
         _ ->
             print_packages(sort_packages())
     end,
@@ -47,7 +47,7 @@ print_packages(Pkgs) ->
                                                                      ,ec_semver:parse(B))
                                                 end, Vsns),
                         VsnStr = join(SortedVsns, <<", ">>),
-                        ?CONSOLE("~s:~n    Versions: ~s~n", [Name, VsnStr])
+                        ?CONSOLE("~ts:~n    Versions: ~ts~n", [Name, VsnStr])
                 end, Pkgs).
 
 sort_packages() ->
@@ -71,4 +71,4 @@ join([Bin | T], Sep) ->
 
 
 info(Description) ->
-    io_lib:format("~s.~n", [Description]).
+    io_lib:format("~ts.~n", [Description]).
diff --git a/src/rebar_prv_path.erl b/src/rebar_prv_path.erl
index d32d2c2..75d38eb 100644
--- a/src/rebar_prv_path.erl
+++ b/src/rebar_prv_path.erl
@@ -75,23 +75,23 @@ paths([{src, true}|Rest], Apps, State, Acc) ->
 paths([{rel, true}|Rest], Apps, State, Acc) ->
     paths(Rest, Apps, State, [rel_dir(State)|Acc]).
 
-base_dir(State) -> io_lib:format("~s", [rebar_dir:base_dir(State)]).
-bin_dir(State)  -> io_lib:format("~s/bin", [rebar_dir:base_dir(State)]).
-lib_dir(State)  -> io_lib:format("~s", [rebar_dir:deps_dir(State)]).
-rel_dir(State)  -> io_lib:format("~s/rel", [rebar_dir:base_dir(State)]).
+base_dir(State) -> io_lib:format("~ts", [rebar_dir:base_dir(State)]).
+bin_dir(State)  -> io_lib:format("~ts/bin", [rebar_dir:base_dir(State)]).
+lib_dir(State)  -> io_lib:format("~ts", [rebar_dir:deps_dir(State)]).
+rel_dir(State)  -> io_lib:format("~ts/rel", [rebar_dir:base_dir(State)]).
 
 ebin_dirs(Apps, State) ->
-    lists:map(fun(App) -> io_lib:format("~s/~s/ebin", [rebar_dir:deps_dir(State), App]) end, Apps).
+    lists:map(fun(App) -> io_lib:format("~ts/~ts/ebin", [rebar_dir:deps_dir(State), App]) end, Apps).
 priv_dirs(Apps, State) ->
-    lists:map(fun(App) -> io_lib:format("~s/~s/priv", [rebar_dir:deps_dir(State), App]) end, Apps).
+    lists:map(fun(App) -> io_lib:format("~ts/~ts/priv", [rebar_dir:deps_dir(State), App]) end, Apps).
 src_dirs(Apps, State) ->
-    lists:map(fun(App) -> io_lib:format("~s/~s/src", [rebar_dir:deps_dir(State), App]) end, Apps).
+    lists:map(fun(App) -> io_lib:format("~ts/~ts/src", [rebar_dir:deps_dir(State), App]) end, Apps).
 
 print_paths_if_exist(Paths, State) ->
     {RawOpts, _} = rebar_state:command_parsed_args(State),
     Sep = proplists:get_value(separator, RawOpts, " "),
     RealPaths = lists:filter(fun(P) -> ec_file:is_dir(P) end, Paths),
-    io:format("~s", [string:join(RealPaths, Sep)]).
+    io:format("~ts", [string:join(RealPaths, Sep)]).
 
 project_deps(State) ->
     Profiles = rebar_state:current_profiles(State),
diff --git a/src/rebar_prv_plugins.erl b/src/rebar_prv_plugins.erl
index c76dae1..4bea3b3 100644
--- a/src/rebar_prv_plugins.erl
+++ b/src/rebar_prv_plugins.erl
@@ -55,19 +55,19 @@ format_error(Reason) ->
 display_plugins(_Header, _Apps, []) ->
     ok;
 display_plugins(Header, Apps, Plugins) ->
-    ?CONSOLE("--- ~s ---", [Header]),
+    ?CONSOLE("--- ~ts ---", [Header]),
     display_plugins(Apps, Plugins),
     ?CONSOLE("", []).
 
 display_plugins(Apps, Plugins) ->
     lists:foreach(fun(Plugin) ->
-                          Name = if is_atom(Plugin) -> ec_cnv:to_binary(Plugin);
-                                    is_tuple(Plugin) -> ec_cnv:to_binary(element(1, Plugin))
+                          Name = if is_atom(Plugin) -> atom_to_binary(Plugin, unicode);
+                                    is_tuple(Plugin) -> rebar_utils:to_binary(element(1, Plugin))
                                  end,
                           case rebar_app_utils:find(Name, Apps) of
                               {ok, _App} ->
-                                  ?CONSOLE("~s", [Name]);
+                                  ?CONSOLE("~ts", [Name]);
                               error ->
-                                  ?DEBUG("Unable to find plugin ~s", [Name])
+                                  ?DEBUG("Unable to find plugin ~ts", [Name])
                           end
                   end, Plugins).
diff --git a/src/rebar_prv_plugins_upgrade.erl b/src/rebar_prv_plugins_upgrade.erl
index 03521c7..7420c83 100644
--- a/src/rebar_prv_plugins_upgrade.erl
+++ b/src/rebar_prv_plugins_upgrade.erl
@@ -44,7 +44,7 @@ do(State) ->
 format_error(no_plugin_arg) ->
     io_lib:format("Must give an installed plugin to upgrade as an argument", []);
 format_error({not_found, Plugin}) ->
-    io_lib:format("Plugin to upgrade not found: ~s", [Plugin]);
+    io_lib:format("Plugin to upgrade not found: ~ts", [Plugin]);
 format_error(Reason) ->
     io_lib:format("~p", [Reason]).
 
diff --git a/src/rebar_prv_report.erl b/src/rebar_prv_report.erl
index d6c8b60..73e9624 100644
--- a/src/rebar_prv_report.erl
+++ b/src/rebar_prv_report.erl
@@ -44,7 +44,7 @@ do(State) ->
     {ok, Vsn} = application:get_key(rebar, vsn),
     {ok, Apps} = application:get_key(rebar, applications),
     [application:load(App) || App <- Apps],
-    Vsns = [io_lib:format("~p: ~s~n", [App, AVsn])
+    Vsns = [io_lib:format("~p: ~ts~n", [App, AVsn])
             || App <- lists:sort(Apps),
                {ok, AVsn} <- [application:get_key(App, vsn)]],
     %% Show OS and versions
@@ -59,10 +59,10 @@ do(State) ->
     %%
     ?CONSOLE(
         "Rebar3 report~n"
-        " version ~s~n"
-        " generated at ~s~n"
+        " version ~ts~n"
+        " generated at ~ts~n"
         "=================~n"
-        "Please submit this along with your issue at ~s "
+        "Please submit this along with your issue at ~ts "
         "(and feel free to edit out private information, if any)~n"
         "-----------------~n"
         "Task: ~ts~n"
@@ -75,11 +75,11 @@ do(State) ->
         "Library directory: ~ts~n"
         "-----------------~n"
         "Loaded Applications:~n"
-        "~s~n"
+        "~ts~n"
         "-----------------~n"
         "Escript path: ~ts~n"
         "Providers:~n"
-        "  ~s",
+        "  ~ts",
         [Vsn, time_to_string(UTC),
          ?ISSUES_URL, Command, Task,
          OS, ERTS, Root, Lib,
@@ -100,4 +100,4 @@ time_to_string({{Y,M,D},{H,Min,S}}) ->
                   [Y,M,D,H,Min,S])).
 
 parse_task(Str) ->
-    hd(re:split(Str, " ")).
+    hd(re:split(Str, " ", [unicode])).
diff --git a/src/rebar_prv_unlock.erl b/src/rebar_prv_unlock.erl
index 7ff0d89..51c57ab 100644
--- a/src/rebar_prv_unlock.erl
+++ b/src/rebar_prv_unlock.erl
@@ -66,7 +66,7 @@ format_error(Reason) ->
 
 handle_unlocks(State, Locks, LockFile) ->
     {Args, _} = rebar_state:command_parsed_args(State),
-    Names = parse_names(ec_cnv:to_binary(proplists:get_value(package, Args, <<"">>))),
+    Names = parse_names(rebar_utils:to_binary(proplists:get_value(package, Args, <<"">>))),
     case [Lock || Lock = {Name, _, _} <- Locks, not lists:member(Name, Names)] of
         [] ->
             file:delete(LockFile);
@@ -77,7 +77,7 @@ handle_unlocks(State, Locks, LockFile) ->
     end.
 
 parse_names(Bin) ->
-    case lists:usort(re:split(Bin, <<" *, *">>, [trim])) of
+    case lists:usort(re:split(Bin, <<" *, *">>, [trim, unicode])) of
         [<<"">>] -> []; % nothing submitted
         Other -> Other
     end.
diff --git a/src/rebar_prv_update.erl b/src/rebar_prv_update.erl
index 046c864..a019c5a 100644
--- a/src/rebar_prv_update.erl
+++ b/src/rebar_prv_update.erl
@@ -150,7 +150,7 @@ update_deps_list(Pkg, PkgVsn, Deps, HexRegistry, State) ->
                             %% and doubled since spaces seem not to be
                             %% enforced
                             {false, Vsn} ->
-                                ?WARN("[~s:~s], Bad dependency version for ~s: ~s.",
+                                ?WARN("[~ts:~ts], Bad dependency version for ~ts: ~ts.",
                                       [Pkg, PkgVsn, Dep, Vsn]),
                                 DepsListAcc;
                             {_, <<"~>", Vsn/binary>>} ->
@@ -202,14 +202,14 @@ valid_vsn(Vsn) ->
     SemVerRegExp = "v?(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)(\\.(0|[1-9][0-9]*))?"
         "(-[0-9a-z-]+(\\.[0-9a-z-]+)*)?(\\+[0-9a-z-]+(\\.[0-9a-z-]+)*)?",
     SupportedVersions = "^(>=?|<=?|~>|==)?\\s*" ++ SemVerRegExp ++ "$",
-    re:run(Vsn, SupportedVersions) =/= nomatch.
+    re:run(Vsn, SupportedVersions, [unicode]) =/= nomatch.
 
 highest_matching({Pkg, PkgVsn, Dep, App}, Vsn, HexRegistry, State, DepsListAcc) ->
     case rebar_packages:find_highest_matching(Pkg, PkgVsn, Dep, Vsn, HexRegistry, State) of
         {ok, HighestDepVsn} ->
             [{App, {pkg, Dep, HighestDepVsn, undefined}} | DepsListAcc];
         none ->
-            ?WARN("[~s:~s] Missing registry entry for package ~s. Try to fix with `rebar3 update`",
+            ?WARN("[~ts:~ts] Missing registry entry for package ~ts. Try to fix with `rebar3 update`",
                   [Pkg, PkgVsn, Dep]),
             DepsListAcc
     end.
@@ -220,7 +220,7 @@ cmp({_Pkg, _PkgVsn, Dep, _App} = Dep1, Vsn, HexRegistry, State, DepsListAcc, Cmp
 
 
 cmp_(undefined, _MinVsn, [], DepsListAcc, {Pkg, PkgVsn, Dep, _App}, _CmpFun) ->
-    ?WARN("[~s:~s] Missing registry entry for package ~s. Try to fix with `rebar3 update`",
+    ?WARN("[~ts:~ts] Missing registry entry for package ~ts. Try to fix with `rebar3 update`",
           [Pkg, PkgVsn, Dep]),
     DepsListAcc;
 cmp_(HighestDepVsn, _MinVsn, [], DepsListAcc, {_Pkg, _PkgVsn, Dep, App}, _CmpFun) ->
@@ -241,7 +241,7 @@ cmpl({_Pkg, _PkgVsn, Dep, _App} = Dep1, Vsn, HexRegistry, State, DepsListAcc, Cm
     cmpl_(undefined, Vsn, Vsns, DepsListAcc, Dep1, CmpFun).
 
 cmpl_(undefined, _MaxVsn, [], DepsListAcc, {Pkg, PkgVsn, Dep, _App}, _CmpFun) ->
-    ?WARN("[~s:~s] Missing registry entry for package ~s. Try to fix with `rebar3 update`",
+    ?WARN("[~ts:~ts] Missing registry entry for package ~ts. Try to fix with `rebar3 update`",
           [Pkg, PkgVsn, Dep]),
     DepsListAcc;
 
diff --git a/src/rebar_prv_upgrade.erl b/src/rebar_prv_upgrade.erl
index 2de30e4..5a7dff8 100644
--- a/src/rebar_prv_upgrade.erl
+++ b/src/rebar_prv_upgrade.erl
@@ -68,7 +68,7 @@ do(State) ->
     ProfileDeps = rebar_state:get(State, {deps, default}, []),
     Deps = [Dep || Dep <- TopDeps ++ ProfileDeps, % TopDeps > ProfileDeps
                    is_atom(Dep) orelse is_atom(element(1, Dep))],
-    Names = parse_names(ec_cnv:to_binary(proplists:get_value(package, Args, <<"">>)), Locks),
+    Names = parse_names(rebar_utils:to_binary(proplists:get_value(package, Args, <<"">>)), Locks),
     DepsDict = deps_dict(rebar_state:all_deps(State)),
     AltDeps = find_non_default_deps(Deps, State),
     FilteredNames = cull_default_names_if_profiles(Names, Deps, State),
@@ -109,7 +109,7 @@ format_error(Reason) ->
     io_lib:format("~p", [Reason]).
 
 parse_names(Bin, Locks) ->
-    case lists:usort(re:split(Bin, <<" *, *">>, [trim])) of
+    case lists:usort(re:split(Bin, <<" *, *">>, [trim, unicode])) of
         %% Nothing submitted, use *all* apps
         [<<"">>] -> [Name || {Name, _, 0} <- Locks];
         [] -> [Name || {Name, _, 0} <- Locks];
@@ -150,7 +150,7 @@ prepare_locks([Name|Names], Deps, Locks, Unlocks, Dict, AltDeps) ->
         {_, _, 0} = Lock ->
             case rebar_utils:tup_find(AtomName, Deps) of
                 false ->
-                    ?WARN("Dependency ~s has been removed and will not be upgraded", [Name]),
+                    ?WARN("Dependency ~ts has been removed and will not be upgraded", [Name]),
                     prepare_locks(Names, Deps, Locks, Unlocks, Dict, AltDeps);
                 Dep ->
                     {Source, NewLocks, NewUnlocks} = prepare_lock(Dep, Lock, Locks, Dict),
@@ -181,7 +181,7 @@ prepare_lock(Dep, Lock, Locks, Dict) ->
         {Name, _, Src} -> {Name, Src};
         _ when is_atom(Dep) ->
             %% version-free package. Must unlock whatever matches in locks
-            {_, Vsn, _} = lists:keyfind(ec_cnv:to_binary(Dep), 1, Locks),
+            {_, Vsn, _} = lists:keyfind(rebar_utils:to_binary(Dep), 1, Locks),
             {Dep, Vsn}
     end,
     Children = all_children(Name1, Dict),
@@ -197,7 +197,7 @@ unlock_children(Children, Locks) ->
 unlock_children(_, [], Locks, Unlocks) ->
     {Locks, Unlocks};
 unlock_children(Children, [App = {Name,_,_} | Apps], Locks, Unlocks) ->
-    case lists:member(ec_cnv:to_binary(Name), Children) of
+    case lists:member(rebar_utils:to_binary(Name), Children) of
         true ->
             unlock_children(Children, Apps, Locks, [App | Unlocks]);
         false ->
@@ -215,7 +215,7 @@ all_children(Name, Dict) ->
     lists:flatten(all_children_(Name, Dict)).
 
 all_children_(Name, Dict) ->
-    case dict:find(ec_cnv:to_binary(Name), Dict) of
+    case dict:find(rebar_utils:to_binary(Name), Dict) of
         {ok, Children} ->
             [Children | [all_children_(Child, Dict) || Child <- Children]];
         error ->
diff --git a/src/rebar_prv_xref.erl b/src/rebar_prv_xref.erl
index f358787..2405ebb 100644
--- a/src/rebar_prv_xref.erl
+++ b/src/rebar_prv_xref.erl
@@ -71,7 +71,7 @@ short_desc() ->
 
 desc() ->
     io_lib:format(
-      "~s~n"
+      "~ts~n"
       "~n"
       "Valid rebar.config options:~n"
       "  ~p~n"
@@ -204,7 +204,7 @@ display_results(XrefResults, QueryResults) ->
      lists:map(fun display_query_result/1, QueryResults)].
 
 display_query_result({Query, Answer, Value}) ->
-    io_lib:format("Query ~s~n answer ~p~n did not match ~p~n",
+    io_lib:format("Query ~ts~n answer ~p~n did not match ~p~n",
                   [Query, Answer, Value]).
 
 display_xref_results_for_type({Type, XrefResults}) ->
@@ -225,37 +225,37 @@ display_xref_result_fun(Type) ->
                 end,
             case Type of
                 undefined_function_calls ->
-                    io_lib:format("~sWarning: ~s calls undefined function ~s (Xref)\n",
+                    io_lib:format("~tsWarning: ~ts calls undefined function ~ts (Xref)\n",
                                   [Source, SMFA, TMFA]);
                 undefined_functions ->
-                    io_lib:format("~sWarning: ~s is undefined function (Xref)\n",
+                    io_lib:format("~tsWarning: ~ts is undefined function (Xref)\n",
                                   [Source, SMFA]);
                 locals_not_used ->
-                    io_lib:format("~sWarning: ~s is unused local function (Xref)\n",
+                    io_lib:format("~tsWarning: ~ts is unused local function (Xref)\n",
                                   [Source, SMFA]);
                 exports_not_used ->
-                    io_lib:format("~sWarning: ~s is unused export (Xref)\n",
+                    io_lib:format("~tsWarning: ~ts is unused export (Xref)\n",
                                   [Source, SMFA]);
                 deprecated_function_calls ->
-                    io_lib:format("~sWarning: ~s calls deprecated function ~s (Xref)\n",
+                    io_lib:format("~tsWarning: ~ts calls deprecated function ~ts (Xref)\n",
                                   [Source, SMFA, TMFA]);
                 deprecated_functions ->
-                    io_lib:format("~sWarning: ~s is deprecated function (Xref)\n",
+                    io_lib:format("~tsWarning: ~ts is deprecated function (Xref)\n",
                                   [Source, SMFA]);
                 Other ->
-                    io_lib:format("~sWarning: ~s - ~s xref check: ~s (Xref)\n",
+                    io_lib:format("~tsWarning: ~ts - ~ts xref check: ~ts (Xref)\n",
                                   [Source, SMFA, TMFA, Other])
             end
     end.
 
 format_mfa({M, F, A}) ->
-    ?FMT("~s:~s/~w", [M, F, A]).
+    ?FMT("~ts:~ts/~w", [M, F, A]).
 
 format_mfa_source(MFA) ->
     case find_mfa_source(MFA) of
         {module_not_found, function_not_found} -> "";
-        {Source, function_not_found} -> ?FMT("~s: ", [Source]);
-        {Source, Line} -> ?FMT("~s:~w: ", [Source, Line])
+        {Source, function_not_found} -> ?FMT("~ts: ", [Source]);
+        {Source, Line} -> ?FMT("~ts:~w: ", [Source, Line])
     end.
 
 %%
diff --git a/src/rebar_state.erl b/src/rebar_state.erl
index 9683709..3314a11 100644
--- a/src/rebar_state.erl
+++ b/src/rebar_state.erl
@@ -182,7 +182,7 @@ all(_, []) ->
 all(Dir, [File|Artifacts]) ->
     case filelib:is_regular(filename:join(Dir, File)) of
         false ->
-            ?DEBUG("Missing artifact ~s", [filename:join(Dir, File)]),
+            ?DEBUG("Missing artifact ~ts", [filename:join(Dir, File)]),
             {false, File};
         true ->
             all(Dir, Artifacts)
@@ -302,9 +302,9 @@ dir(State=#state_t{}, Dir) ->
 
 deps_names(Deps) when is_list(Deps) ->
     lists:map(fun(Dep) when is_tuple(Dep) ->
-                      ec_cnv:to_binary(element(1, Dep));
+                      rebar_utils:to_binary(element(1, Dep));
                  (Dep) when is_atom(Dep) ->
-                      ec_cnv:to_binary(Dep)
+                      rebar_utils:to_binary(Dep)
               end, Deps);
 deps_names(State) ->
     Deps = rebar_state:get(State, deps, []),
diff --git a/src/rebar_templater.erl b/src/rebar_templater.erl
index 1c28788..75190ec 100644
--- a/src/rebar_templater.erl
+++ b/src/rebar_templater.erl
@@ -129,7 +129,7 @@ default_author_and_email() ->
             %% Ok, try mecurial
             case rebar_utils:sh("hg showconfig ui.username", [return_on_error]) of
                 {ok, NameEmail} ->
-                    case re:run(NameEmail, "^(.*) <(.*)>$", [{capture, [1,2], list}]) of
+                    case re:run(NameEmail, "^(.*) <(.*)>$", [{capture, [1,2], list}, unicode]) of
                         {match, [Name, Email]} ->
                             {Name, Email};
                         _ ->
@@ -169,7 +169,7 @@ maybe_warn_about_name(Vars) ->
         invalid ->
            ?WARN("The 'name' variable is often associated with Erlang "
                  "module names and/or file names. The value submitted "
-                 "(~s) isn't an unquoted Erlang atom. Templates "
+                 "(~ts) isn't an unquoted Erlang atom. Templates "
                  "generated may contain errors.",
                  [Name]);
         valid ->
@@ -189,7 +189,7 @@ validate_atom(Str) ->
 
 %% Run template instructions one at a time.
 execute_template([], _, {Template,_,_}, _, _) ->
-    ?DEBUG("Template ~s applied", [Template]),
+    ?DEBUG("Template ~ts applied", [Template]),
     ok;
 %% We can't execute the description
 execute_template([{description, _} | Terms], Files, Template, Vars, Force) ->
@@ -242,7 +242,7 @@ execute_template([{template, From, To} | Terms], Files, {Template, Type, Cwd}, V
     execute_template(Terms, Files, {Template, Type, Cwd}, Vars, Force);
 %% Unknown
 execute_template([Instruction|Terms], Files, Tpl={Template,_,_}, Vars, Force) ->
-    ?WARN("Unknown template instruction ~p in template ~s",
+    ?WARN("Unknown template instruction ~p in template ~ts",
           [Instruction, Template]),
     execute_template(Terms, Files, Tpl, Vars, Force).
 
@@ -305,7 +305,7 @@ cache_escript_files(State) ->
 find_escript_templates(Files) ->
     [{escript, Name}
      || {Name, _Bin} <- Files,
-        re:run(Name, ?TEMPLATE_RE, [{capture, none}]) == match].
+        re:run(Name, ?TEMPLATE_RE, [{capture, none}, unicode]) == match].
 
 find_localinstall_templates(_State) ->
     Templates = rebar_utils:find_files(code:priv_dir(rebar), ?TEMPLATE_RE),
@@ -374,7 +374,7 @@ prioritize_templates([{Name, Type, File} | Rest], Valid) ->
             prioritize_templates(Rest, Valid);
         {_, file, _} ->
             ?DEBUG("Skipping template ~p, due to presence of a custom "
-                   "template at ~s", [Name, File]),
+                   "template at ~ts", [Name, File]),
             prioritize_templates(Rest, Valid)
     end.
 
@@ -429,10 +429,10 @@ write_file(Output, Data, Force) ->
             ok = filelib:ensure_dir(Output),
             case {Force, FileExists} of
                 {true, true} ->
-                    ?INFO("Writing ~s (forcibly overwriting)",
+                    ?INFO("Writing ~ts (forcibly overwriting)",
                              [Output]);
                 _ ->
-                    ?INFO("Writing ~s", [Output])
+                    ?INFO("Writing ~ts", [Output])
             end,
             case file:write_file(Output, Data) of
                 ok ->
@@ -449,4 +449,4 @@ write_file(Output, Data, Force) ->
 %% Render a binary to a string, using mustache and the specified context
 %%
 render(Bin, Context) ->
-    bbmustache:render(ec_cnv:to_binary(Bin), Context, [{key_type, atom}]).
+    bbmustache:render(rebar_utils:to_binary(Bin), Context, [{key_type, atom}]).
diff --git a/src/rebar_utils.erl b/src/rebar_utils.erl
index c684e2d..016847e 100644
--- a/src/rebar_utils.erl
+++ b/src/rebar_utils.erl
@@ -55,6 +55,8 @@
          get_arch/0,
          wordsize/0,
          deps_to_binary/1,
+         to_binary/1,
+         to_list/1,
          tup_dedup/1,
          tup_umerge/2,
          tup_sort/1,
@@ -115,7 +117,7 @@ filtermap(F, [Hd|Tail]) ->
 filtermap(F, []) when is_function(F, 1) -> [].
 
 is_arch(ArchRegex) ->
-    case re:run(get_arch(), ArchRegex, [{capture, none}]) of
+    case re:run(get_arch(), ArchRegex, [{capture, none}, unicode]) of
         match ->
             true;
         nomatch ->
@@ -142,7 +144,7 @@ wordsize() ->
     end.
 
 sh_send(Command0, String, Options0) ->
-    ?INFO("sh_send info:\n\tcwd: ~p\n\tcmd: ~s < ~s\n",
+    ?INFO("sh_send info:\n\tcwd: ~p\n\tcmd: ~ts < ~ts\n",
           [rebar_dir:get_cwd(), Command0, String]),
     ?DEBUG("\topts: ~p\n", [Options0]),
 
@@ -171,7 +173,7 @@ sh_send(Command0, String, Options0) ->
 %% Val = string() | false
 %%
 sh(Command0, Options0) ->
-    ?DEBUG("sh info:\n\tcwd: ~p\n\tcmd: ~s\n", [rebar_dir:get_cwd(), Command0]),
+    ?DEBUG("sh info:\n\tcwd: ~p\n\tcmd: ~ts\n", [rebar_dir:get_cwd(), Command0]),
     ?DEBUG("\topts: ~p\n", [Options0]),
 
     DefaultOptions = [{use_stdout, false}, debug_and_abort_on_error],
@@ -184,7 +186,7 @@ sh(Command0, Options0) ->
     Command = lists:flatten(patch_on_windows(Command0, proplists:get_value(env, Options, []))),
     PortSettings = proplists:get_all_values(port_settings, Options) ++
         [exit_status, {line, 16384}, use_stdio, stderr_to_stdout, hide, eof],
-    ?DEBUG("Port Cmd: ~s\nPort Opts: ~p\n", [Command, PortSettings]),
+    ?DEBUG("Port Cmd: ~ts\nPort Opts: ~p\n", [Command, PortSettings]),
     Port = open_port({spawn, Command}, PortSettings),
 
     try
@@ -232,7 +234,7 @@ deprecated(Old, New, When) ->
       <<"WARNING: deprecated ~p option used~n"
         "Option '~p' has been deprecated~n"
         "in favor of '~p'.~n"
-        "'~p' will be removed ~s.~n">>,
+        "'~p' will be removed ~ts.~n">>,
       [Old, Old, New, Old, When]).
 
 %% for use by `do` task
@@ -244,11 +246,17 @@ args_to_tasks(Args) -> new_task(Args, []).
 deps_to_binary([]) ->
     [];
 deps_to_binary([{Name, _, Source} | T]) ->
-    [{ec_cnv:to_binary(Name), Source} | deps_to_binary(T)];
+    [{to_binary(Name), Source} | deps_to_binary(T)];
 deps_to_binary([{Name, Source} | T]) ->
-    [{ec_cnv:to_binary(Name), Source} | deps_to_binary(T)];
+    [{to_binary(Name), Source} | deps_to_binary(T)];
 deps_to_binary([Name | T]) ->
-    [ec_cnv:to_binary(Name) | deps_to_binary(T)].
+    [to_binary(Name) | deps_to_binary(T)].
+
+to_binary(A) when is_atom(A) -> atom_to_binary(A, unicode);
+to_binary(Str) -> unicode:characters_to_binary(Str).
+
+to_list(A) when is_atom(A) -> atom_to_list(A);
+to_list(Str) -> unicode:characters_to_list(Str).
 
 tup_dedup(List) ->
     tup_dedup_(tup_sort(List)).
@@ -396,10 +404,10 @@ check_min_otp_version(MinOtpVersion) ->
 
     case ParsedVsn >= ParsedMin of
         true ->
-            ?DEBUG("~s satisfies the requirement for minimum OTP version ~s",
+            ?DEBUG("~ts satisfies the requirement for minimum OTP version ~ts",
                    [OtpRelease, MinOtpVersion]);
         false ->
-            ?ABORT("OTP release ~s or later is required. Version in use: ~s",
+            ?ABORT("OTP release ~ts or later is required. Version in use: ~ts",
                    [MinOtpVersion, OtpRelease])
     end.
 
@@ -415,16 +423,16 @@ check_blacklisted_otp_versions(BlacklistedRegexes) ->
 abort_if_blacklisted(BlacklistedRegex, OtpRelease) ->
     case re:run(OtpRelease, BlacklistedRegex, [{capture, none}]) of
         match ->
-            ?ABORT("OTP release ~s matches blacklisted version ~s",
+            ?ABORT("OTP release ~ts matches blacklisted version ~ts",
                    [OtpRelease, BlacklistedRegex]);
         nomatch ->
-            ?DEBUG("~s does not match blacklisted OTP version ~s",
+            ?DEBUG("~ts does not match blacklisted OTP version ~ts",
                    [OtpRelease, BlacklistedRegex])
     end.
 
 user_agent() ->
     {ok, Vsn} = application:get_key(rebar, vsn),
-    ?FMT("Rebar/~s (OTP/~s)", [Vsn, otp_release()]).
+    ?FMT("Rebar/~ts (OTP/~ts)", [Vsn, otp_release()]).
 
 reread_config(ConfigList) ->
     %% NB: we attempt to mimic -config here, which survives app reload,
@@ -457,7 +465,7 @@ version_tuple(OtpRelease) ->
         {match, [_Full, Maj]} ->
             {list_to_integer(Maj), 0, 0};
         nomatch ->
-            ?ABORT("Minimum OTP release unable to be parsed: ~s", [OtpRelease])
+            ?ABORT("Minimum OTP release unable to be parsed: ~ts", [OtpRelease])
     end.
 
 otp_release() ->
@@ -510,7 +518,7 @@ patch_on_windows(Cmd, Env) ->
                                end, Cmd, Env),
             %% Remove left-over vars
             re:replace(Cmd1, "\\\$\\w+|\\\${\\w+}", "",
-                       [global, {return, list}]);
+                       [global, {return, list}, unicode]);
         _ ->
             Cmd
     end.
@@ -529,7 +537,7 @@ expand_env_variable(InStr, VarName, RawVarValue) ->
             VarValue = re:replace(RawVarValue, "\\\\", "\\\\\\\\", ReOpts),
             %% Use a regex to match/replace:
             %% Given variable "FOO": match $FOO\s | $FOOeol | ${FOO}
-            RegEx = io_lib:format("\\\$(~s(\\W|$)|{~s})", [VarName, VarName]),
+            RegEx = io_lib:format("\\\$(~ts(\\W|$)|{~ts})", [VarName, VarName]),
             re:replace(InStr, RegEx, [VarValue, "\\2"], ReOpts)
     end.
 
@@ -554,7 +562,7 @@ expand_sh_flag(use_stdout) ->
     {output_handler,
      fun(Line, Acc) ->
              %% Line already has a newline so don't use ?CONSOLE which adds one
-             io:format("~s", [Line]),
+             io:format("~ts", [Line]),
              [Line | Acc]
      end};
 expand_sh_flag({use_stdout, false}) ->
@@ -577,23 +585,23 @@ log_msg_and_abort(Message) ->
 -spec debug_log_msg_and_abort(string()) -> err_handler().
 debug_log_msg_and_abort(Message) ->
     fun(Command, {Rc, Output}) ->
-            ?DEBUG("sh(~s)~n"
+            ?DEBUG("sh(~ts)~n"
                   "failed with return code ~w and the following output:~n"
-                  "~s", [Command, Rc, Output]),
+                  "~ts", [Command, Rc, Output]),
             ?ABORT(Message, [])
     end.
 
 -spec log_and_abort(string(), {integer(), string()}) -> no_return().
 log_and_abort(Command, {Rc, Output}) ->
-    ?ABORT("sh(~s)~n"
+    ?ABORT("sh(~ts)~n"
           "failed with return code ~w and the following output:~n"
-          "~s", [Command, Rc, Output]).
+          "~ts", [Command, Rc, Output]).
 
 -spec debug_and_abort(string(), {integer(), string()}) -> no_return().
 debug_and_abort(Command, {Rc, Output}) ->
-    ?DEBUG("sh(~s)~n"
+    ?DEBUG("sh(~ts)~n"
           "failed with return code ~w and the following output:~n"
-          "~s", [Command, Rc, Output]),
+          "~ts", [Command, Rc, Output]),
     throw(rebar_abort).
 
 sh_loop(Port, Fun, Acc) ->
@@ -662,7 +670,7 @@ vcs_vsn(Vcs, Dir, Resources) ->
         unknown ->
             ?ABORT("vcs_vsn: Unknown vsn format: ~p", [Vcs]);
         {error, Reason} ->
-            ?ABORT("vcs_vsn: ~s", [Reason])
+            ?ABORT("vcs_vsn: ~ts", [Reason])
     end.
 
 %% Temp work around for repos like relx that use "semver"
@@ -779,7 +787,7 @@ cleanup_code_path(OrigPath) ->
 
 new_task([], Acc) -> lists:reverse(Acc);
 new_task([TaskList|Rest], Acc) ->
-    case re:split(TaskList, ",", [{return, list}, {parts, 2}]) of
+    case re:split(TaskList, ",", [{return, list}, {parts, 2}, unicode]) of
         %% `do` consumes all remaining args
         ["do" = Task] ->
             lists:reverse([{Task, Rest}|Acc]);
@@ -806,7 +814,7 @@ arg_or_flag(["-" ++ _ = Flag|Rest], [{Task, Args}|Acc]) ->
     end;
 %% an argument or a sequence of arguments
 arg_or_flag([ArgList|Rest], [{Task, Args}|Acc]) ->
-    case re:split(ArgList, ",", [{return, list}, {parts, 2}]) of
+    case re:split(ArgList, ",", [{return, list}, {parts, 2}, unicode]) of
         %% single arg terminated by a comma
         [Arg, ""]   -> new_task(Rest, [{Task,
                                         lists:reverse([Arg|Args])}|Acc]);
@@ -857,15 +865,18 @@ url_append_path(Url, ExtraPath) ->
 escape_chars(Str) when is_atom(Str) ->
     escape_chars(atom_to_list(Str));
 escape_chars(Str) ->
-    re:replace(Str, "([ ()?`!$&;\"\'])", "\\\\&", [global, {return, list}]).
+    re:replace(Str, "([ ()?`!$&;\"\'])", "\\\\&",
+               [global, {return, list}, unicode]).
 
 %% "escape inside these"
 escape_double_quotes(Str) ->
-    re:replace(Str, "([\"\\\\`!$&*;])", "\\\\&", [global, {return, list}]).
+    re:replace(Str, "([\"\\\\`!$&*;])", "\\\\&",
+               [global, {return, list}, unicode]).
 
 %% "escape inside these" but allow *
 escape_double_quotes_weak(Str) ->
-    re:replace(Str, "([\"\\\\`!$&;])", "\\\\&", [global, {return, list}]).
+    re:replace(Str, "([\"\\\\`!$&;])", "\\\\&",
+               [global, {return, list}, unicode]).
 
 info_useless(Old, New) ->
     [?INFO("App ~ts is no longer needed and can be deleted.", [Name])