summaryrefslogtreecommitdiff
path: root/src/rebar_deps.erl
blob: c79e4c1ed2732631bc3d14b8a7f51429a06f4f11 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
%% -*- erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ts=4 sw=4 et
%% -------------------------------------------------------------------
%%
%% rebar: Erlang Build Tools
%%
%% Copyright (c) 2009 Dave Smith (dizzyd@dizzyd.com)
%%
%% Permission is hereby granted, free of charge, to any person obtaining a copy
%% of this software and associated documentation files (the "Software"), to deal
%% in the Software without restriction, including without limitation the rights
%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
%% copies of the Software, and to permit persons to whom the Software is
%% furnished to do so, subject to the following conditions:
%%
%% The above copyright notice and this permission notice shall be included in
%% all copies or substantial portions of the Software.
%%
%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
%% THE SOFTWARE.
%% -------------------------------------------------------------------
-module(rebar_deps).

-include("rebar.hrl").

-export([preprocess/2,
         postprocess/2,
         compile/2,
         setup_env/1,
         'check-deps'/2,
         'get-deps'/2,
         'update-deps'/2,
         'delete-deps'/2,
         'list-deps'/2]).


-record(dep, { dir,
               app,
               vsn_regex,
               source }).

%% ===================================================================
%% Public API
%% ===================================================================

preprocess(Config, _) ->
    %% Side effect to set deps_dir globally for all dependencies from
    %% top level down. Means the root deps_dir is honoured or the default
    %% used globally since it will be set on the first time through here
    Config1 = set_shared_deps_dir(Config, get_shared_deps_dir(Config, [])),

    %% Get the list of deps for the current working directory and identify those
    %% deps that are available/present.
    Deps = rebar_config:get_local(Config1, deps, []),
    {Config2, {AvailableDeps, MissingDeps}} = find_deps(Config1, find, Deps),

    ?DEBUG("Available deps: ~p\n", [AvailableDeps]),
    ?DEBUG("Missing deps  : ~p\n", [MissingDeps]),

    %% Add available deps to code path
    Config3 = update_deps_code_path(Config2, AvailableDeps),

    %% If skip_deps=true, mark each dep dir as a skip_dir w/ the core so that
    %% the current command doesn't run on the dep dir. However, pre/postprocess
    %% WILL run (and we want it to) for transitivity purposes.
    %%
    %% Also, if skip_deps=comma,separated,app,list, then only the given
    %% dependencies are skipped.
    NewConfig = case rebar_config:get_global(Config3, skip_deps, false) of
        "true" ->
            lists:foldl(
                fun(#dep{dir = Dir}, C) ->
                        rebar_config:set_skip_dir(C, Dir)
                end, Config3, AvailableDeps);
        Apps when is_list(Apps) ->
            SkipApps = [list_to_atom(App) || App <- string:tokens(Apps, ",")],
            lists:foldl(
                fun(#dep{dir = Dir, app = App}, C) ->
                        case lists:member(App, SkipApps) of
                            true -> rebar_config:set_skip_dir(C, Dir);
                            false -> C
                        end
                end, Config3, AvailableDeps);
        _ ->
            Config3
    end,

    %% Return all the available dep directories for process
    {ok, NewConfig, dep_dirs(AvailableDeps)}.

postprocess(Config, _) ->
    case rebar_config:get_xconf(Config, ?MODULE, undefined) of
        undefined ->
            {ok, []};
        Dirs ->
            NewConfig = rebar_config:erase_xconf(Config, ?MODULE),
            {ok, NewConfig, Dirs}
    end.

compile(Config, AppFile) ->
    'check-deps'(Config, AppFile).

%% set REBAR_DEPS_DIR and ERL_LIBS environment variables
setup_env(Config) ->
    {true, DepsDir} = get_deps_dir(Config),
    %% include rebar's DepsDir in ERL_LIBS
    Separator = case os:type() of
                    {win32, nt} ->
                        ";";
                    _ ->
                        ":"
                end,
    ERL_LIBS = case os:getenv("ERL_LIBS") of
                   false ->
                       {"ERL_LIBS", DepsDir};
                   PrevValue ->
                       {"ERL_LIBS", DepsDir ++ Separator ++ PrevValue}
               end,
    [{"REBAR_DEPS_DIR", DepsDir}, ERL_LIBS].

'check-deps'(Config, _) ->
    %% Get the list of immediate (i.e. non-transitive) deps that are missing
    Deps = rebar_config:get_local(Config, deps, []),
    case find_deps(Config, find, Deps) of
        {Config1, {_, []}} ->
            %% No missing deps
            {ok, Config1};
        {_Config1, {_, MissingDeps}} ->
            lists:foreach(fun (#dep{app=App, vsn_regex=Vsn, source=Src}) ->
                                  ?CONSOLE("Dependency not available: "
                                           "~p-~s (~p)\n", [App, Vsn, Src])
                          end, MissingDeps),
            ?FAIL
    end.

'get-deps'(Config, _) ->
    %% Determine what deps are available and missing
    Deps = rebar_config:get_local(Config, deps, []),
    {Config1, {_AvailableDeps, MissingDeps}} = find_deps(Config, find, Deps),
    MissingDeps1 = [D || D <- MissingDeps, D#dep.source =/= undefined],

    %% For each missing dep with a specified source, try to pull it.
    {Config2, PulledDeps} =
        lists:foldl(fun(D, {C, PulledDeps0}) ->
                            {C1, D1} = use_source(C, D),
                            {C1, [D1 | PulledDeps0]}
                    end, {Config1, []}, MissingDeps1),

    %% Add each pulled dep to our list of dirs for post-processing. This yields
    %% the necessary transitivity of the deps
    {ok, save_dep_dirs(Config2, lists:reverse(PulledDeps))}.

'update-deps'(Config, _) ->
    %% Determine what deps are required
    RawDeps = rebar_config:get_local(Config, deps, []),
    {Config1, Deps} = find_deps(Config, read, RawDeps),

    %% Update each dep
    UpdatedDeps = [update_source(Config1, D)
                   || D <- Deps, D#dep.source =/= undefined],

    %% Add each updated dep to our list of dirs for post-processing. This yields
    %% the necessary transitivity of the deps
    {ok, save_dep_dirs(Config1, UpdatedDeps)}.

'delete-deps'(Config, _) ->
    %% Delete all the available deps in our deps/ directory, if any
    {true, DepsDir} = get_deps_dir(Config),
    Deps = rebar_config:get_local(Config, deps, []),
    {Config1, {AvailableDeps, _}} = find_deps(Config, find, Deps),
    _ = [delete_dep(D)
         || D <- AvailableDeps,
            lists:prefix(DepsDir, D#dep.dir)],
    {ok, Config1}.

'list-deps'(Config, _) ->
    Deps = rebar_config:get_local(Config, deps, []),
    case find_deps(Config, find, Deps) of
        {Config1, {AvailDeps, []}} ->
            lists:foreach(fun(Dep) -> print_source(Dep) end, AvailDeps),
            {ok, Config1};
        {_, MissingDeps} ->
            ?ABORT("Missing dependencies: ~p\n", [MissingDeps])
    end.

%% ===================================================================
%% Internal functions
%% ===================================================================

%% Added because of trans deps,
%% need all deps in same dir and should be the one set by the root rebar.config
%% Sets a default if root config has no deps_dir set
set_shared_deps_dir(Config, []) ->
    rebar_config:set_xconf(Config, deps_dir,
                           rebar_config:get_local(Config, deps_dir, "deps"));
set_shared_deps_dir(Config, _DepsDir) ->
    Config.

get_shared_deps_dir(Config, Default) ->
    rebar_config:get_xconf(Config, deps_dir, Default).

get_deps_dir(Config) ->
    get_deps_dir(Config, "").

get_deps_dir(Config, App) ->
    BaseDir = rebar_config:get_xconf(Config, base_dir, []),
    DepsDir = get_shared_deps_dir(Config, "deps"),
    {true, filename:join([BaseDir, DepsDir, App])}.

dep_dirs(Deps) ->
    [D#dep.dir || D <- Deps].

save_dep_dirs(Config, Deps) ->
    rebar_config:set_xconf(Config, ?MODULE, dep_dirs(Deps)).

get_lib_dir(App) ->
    %% Find App amongst the reachable lib directories
    %% Returns either the found path or a tagged tuple with a boolean
    %% to match get_deps_dir's return type
    case code:lib_dir(App) of
        {error, bad_name} -> {false, bad_name};
        Path -> {true, Path}
    end.

update_deps_code_path(Config, []) ->
    Config;
update_deps_code_path(Config, [Dep | Rest]) ->
    Config2 =
        case is_app_available(Config, Dep#dep.app,
                              Dep#dep.vsn_regex, Dep#dep.dir) of
            {Config1, {true, _}} ->
                Dir = filename:join(Dep#dep.dir, "ebin"),
                ok = filelib:ensure_dir(filename:join(Dir, "dummy")),
                ?DEBUG("Adding ~s to code path~n", [Dir]),
                true = code:add_patha(Dir),
                Config1;
            {Config1, {false, _}} ->
                Config1
        end,
    update_deps_code_path(Config2, Rest).

find_deps(Config, find=Mode, Deps) ->
    find_deps(Config, Mode, Deps, {[], []});
find_deps(Config, read=Mode, Deps) ->
    find_deps(Config, Mode, Deps, []).

find_deps(Config, find, [], {Avail, Missing}) ->
    {Config, {lists:reverse(Avail), lists:reverse(Missing)}};
find_deps(Config, read, [], Deps) ->
    {Config, lists:reverse(Deps)};
find_deps(Config, Mode, [App | Rest], Acc) when is_atom(App) ->
    find_deps(Config, Mode, [{App, ".*", undefined} | Rest], Acc);
find_deps(Config, Mode, [{App, VsnRegex} | Rest], Acc) when is_atom(App) ->
    find_deps(Config, Mode, [{App, VsnRegex, undefined} | Rest], Acc);
find_deps(Config, Mode, [{App, VsnRegex, Source} | Rest], Acc) ->
    Dep = #dep { app = App,
                 vsn_regex = VsnRegex,
                 source = Source },
    {Config1, {Availability, FoundDir}} = find_dep(Config, Dep),
    find_deps(Config1, Mode, Rest,
              acc_deps(Mode, Availability, Dep, FoundDir, Acc));
find_deps(_Config, _Mode, [Other | _Rest], _Acc) ->
    ?ABORT("Invalid dependency specification ~p in ~s\n",
           [Other, rebar_utils:get_cwd()]).

find_dep(Config, Dep) ->
    %% Find a dep based on its source,
    %% e.g. {git, "https://github.com/mochi/mochiweb.git", "HEAD"}
    %% Deps with a source must be found (or fetched) locally.
    %% Those without a source may be satisfied from lib dir (get_lib_dir).
    find_dep(Config, Dep, Dep#dep.source).

find_dep(Config, Dep, undefined) ->
    %% 'source' is undefined.  If Dep is not satisfied locally,
    %% go ahead and find it amongst the lib_dir's.
    case find_dep_in_dir(Config, Dep, get_deps_dir(Config, Dep#dep.app)) of
        {_Config1, {avail, _Dir}} = Avail ->
            Avail;
        {Config1, {missing, _}} ->
            find_dep_in_dir(Config1, Dep, get_lib_dir(Dep#dep.app))
    end;
find_dep(Config, Dep, _Source) ->
    %% _Source is defined.  Regardless of what it is, we must find it
    %% locally satisfied or fetch it from the original source
    %% into the project's deps
    find_dep_in_dir(Config, Dep, get_deps_dir(Config, Dep#dep.app)).

find_dep_in_dir(Config, _Dep, {false, Dir}) ->
    {Config, {missing, Dir}};
find_dep_in_dir(Config, Dep, {true, Dir}) ->
    App = Dep#dep.app,
    VsnRegex = Dep#dep.vsn_regex,
    case is_app_available(Config, App, VsnRegex, Dir) of
        {Config1, {true, _AppFile}} -> {Config1, {avail, Dir}};
        {Config1, {false, _}}       -> {Config1, {missing, Dir}}
    end.

acc_deps(find, avail, Dep, AppDir, {Avail, Missing}) ->
    {[Dep#dep { dir = AppDir } | Avail], Missing};
acc_deps(find, missing, Dep, AppDir, {Avail, Missing}) ->
    {Avail, [Dep#dep { dir = AppDir } | Missing]};
acc_deps(read, _, Dep, AppDir, Acc) ->
    [Dep#dep { dir = AppDir } | Acc].

delete_dep(D) ->
    case filelib:is_dir(D#dep.dir) of
        true ->
            ?INFO("Deleting dependency: ~s\n", [D#dep.dir]),
            rebar_file_utils:rm_rf(D#dep.dir);
        false ->
            ok
    end.

require_source_engine(Source) ->
    true = source_engine_avail(Source),
    ok.

is_app_available(Config, App, VsnRegex, Path) ->
    ?DEBUG("is_app_available, looking for App ~p with Path ~p~n", [App, Path]),
    case rebar_app_utils:is_app_dir(Path) of
        {true, AppFile} ->
            case rebar_app_utils:app_name(Config, AppFile) of
                {Config1, App} ->
                    {Config2, Vsn} = rebar_app_utils:app_vsn(Config1, AppFile),
                    ?INFO("Looking for ~s-~s ; found ~s-~s at ~s\n",
                          [App, VsnRegex, App, Vsn, Path]),
                    case re:run(Vsn, VsnRegex, [{capture, none}]) of
                        match ->
                            {Config2, {true, Path}};
                        nomatch ->
                            ?WARN("~s has version ~p; requested regex was ~s\n",
                                  [AppFile, Vsn, VsnRegex]),
                            {Config2,
                             {false, {version_mismatch,
                                      {AppFile,
                                       {expected, VsnRegex}, {has, Vsn}}}}}
                    end;
                {Config1, OtherApp} ->
                    ?WARN("~s has application id ~p; expected ~p\n",
                          [AppFile, OtherApp, App]),
                    {Config1,
                     {false, {name_mismatch,
                              {AppFile, {expected, App}, {has, OtherApp}}}}}
            end;
        false ->
            ?WARN("Expected ~s to be an app dir (containing ebin/*.app), "
                  "but no .app found.\n", [Path]),
            {Config, {false, {missing_app_file, Path}}}
    end.

use_source(Config, Dep) ->
    use_source(Config, Dep, 3).

use_source(_Config, Dep, 0) ->
    ?ABORT("Failed to acquire source from ~p after 3 tries.\n",
           [Dep#dep.source]);
use_source(Config, Dep, Count) ->
    case filelib:is_dir(Dep#dep.dir) of
        true ->
            %% Already downloaded -- verify the versioning matches the regex
            case is_app_available(Config, Dep#dep.app,
                                  Dep#dep.vsn_regex, Dep#dep.dir) of
                {Config1, {true, _}} ->
                    Dir = filename:join(Dep#dep.dir, "ebin"),
                    ok = filelib:ensure_dir(filename:join(Dir, "dummy")),
                    %% Available version matches up -- we're good to go;
                    %% add the app dir to our code path
                    true = code:add_patha(Dir),
                    {Config1, Dep};
                {_Config1, {false, Reason}} ->
                    %% The app that was downloaded doesn't match up (or had
                    %% errors or something). For the time being, abort.
                    ?ABORT("Dependency dir ~s failed application validation "
                           "with reason:~n~p.\n", [Dep#dep.dir, Reason])
            end;
        false ->
            ?CONSOLE("Pulling ~p from ~p\n", [Dep#dep.app, Dep#dep.source]),
            require_source_engine(Dep#dep.source),
            {true, TargetDir} = get_deps_dir(Config, Dep#dep.app),
            download_source(TargetDir, Dep#dep.source),
            use_source(Config, Dep#dep { dir = TargetDir }, Count-1)
    end.

download_source(AppDir, {hg, Url, Rev}) ->
    ok = filelib:ensure_dir(AppDir),
    rebar_utils:sh(?FMT("hg clone -U ~s ~s", [Url, filename:basename(AppDir)]),
                   [{cd, filename:dirname(AppDir)}]),
    rebar_utils:sh(?FMT("hg update ~s", [Rev]), [{cd, AppDir}]);
download_source(AppDir, {git, Url}) ->
    download_source(AppDir, {git, Url, {branch, "HEAD"}});
download_source(AppDir, {git, Url, ""}) ->
    download_source(AppDir, {git, Url, {branch, "HEAD"}});
download_source(AppDir, {git, Url, {branch, Branch}}) ->
    ok = filelib:ensure_dir(AppDir),
    rebar_utils:sh(?FMT("git clone -n ~s ~s", [Url, filename:basename(AppDir)]),
                   [{cd, filename:dirname(AppDir)}]),
    rebar_utils:sh(?FMT("git checkout -q origin/~s", [Branch]), [{cd, AppDir}]);
download_source(AppDir, {git, Url, {tag, Tag}}) ->
    ok = filelib:ensure_dir(AppDir),
    rebar_utils:sh(?FMT("git clone -n ~s ~s", [Url, filename:basename(AppDir)]),
                   [{cd, filename:dirname(AppDir)}]),
    rebar_utils:sh(?FMT("git checkout -q ~s", [Tag]), [{cd, AppDir}]);
download_source(AppDir, {git, Url, Rev}) ->
    ok = filelib:ensure_dir(AppDir),
    rebar_utils:sh(?FMT("git clone -n ~s ~s", [Url, filename:basename(AppDir)]),
                   [{cd, filename:dirname(AppDir)}]),
    rebar_utils:sh(?FMT("git checkout -q ~s", [Rev]), [{cd, AppDir}]);
download_source(AppDir, {bzr, Url, Rev}) ->
    ok = filelib:ensure_dir(AppDir),
    rebar_utils:sh(?FMT("bzr branch -r ~s ~s ~s",
                        [Rev, Url, filename:basename(AppDir)]),
                   [{cd, filename:dirname(AppDir)}]);
download_source(AppDir, {svn, Url, Rev}) ->
    ok = filelib:ensure_dir(AppDir),
    rebar_utils:sh(?FMT("svn checkout -r ~s ~s ~s",
                        [Rev, Url, filename:basename(AppDir)]),
                   [{cd, filename:dirname(AppDir)}]);
download_source(AppDir, {rsync, Url}) ->
    ok = filelib:ensure_dir(AppDir),
    rebar_utils:sh(?FMT("rsync -az --delete ~s/ ~s", [Url, AppDir]), []).

update_source(Config, Dep) ->
    %% It's possible when updating a source, that a given dep does not have a
    %% VCS directory, such as when a source archive is built of a project, with
    %% all deps already downloaded/included. So, verify that the necessary VCS
    %% directory exists before attempting to do the update.
    {true, AppDir} = get_deps_dir(Config, Dep#dep.app),
    case has_vcs_dir(element(1, Dep#dep.source), AppDir) of
        true ->
            ?CONSOLE("Updating ~p from ~p\n", [Dep#dep.app, Dep#dep.source]),
            require_source_engine(Dep#dep.source),
            update_source1(AppDir, Dep#dep.source),
            Dep;
        false ->
            ?WARN("Skipping update for ~p: "
                  "no VCS directory available!\n", [Dep]),
            Dep
    end.

update_source1(AppDir, {git, Url}) ->
    update_source1(AppDir, {git, Url, {branch, "HEAD"}});
update_source1(AppDir, {git, Url, ""}) ->
    update_source1(AppDir, {git, Url, {branch, "HEAD"}});
update_source1(AppDir, {git, _Url, {branch, Branch}}) ->
    ShOpts = [{cd, AppDir}],
    rebar_utils:sh("git fetch origin", ShOpts),
    rebar_utils:sh(?FMT("git checkout -q origin/~s", [Branch]), ShOpts);
update_source1(AppDir, {git, _Url, {tag, Tag}}) ->
    ShOpts = [{cd, AppDir}],
    rebar_utils:sh("git fetch --tags origin", ShOpts),
    rebar_utils:sh(?FMT("git checkout -q ~s", [Tag]), ShOpts);
update_source1(AppDir, {git, _Url, Refspec}) ->
    ShOpts = [{cd, AppDir}],
    rebar_utils:sh("git fetch origin", ShOpts),
    rebar_utils:sh(?FMT("git checkout -q ~s", [Refspec]), ShOpts);
update_source1(AppDir, {svn, _Url, Rev}) ->
    rebar_utils:sh(?FMT("svn up -r ~s", [Rev]), [{cd, AppDir}]);
update_source1(AppDir, {hg, _Url, Rev}) ->
    rebar_utils:sh(?FMT("hg pull -u -r ~s", [Rev]), [{cd, AppDir}]);
update_source1(AppDir, {bzr, _Url, Rev}) ->
    rebar_utils:sh(?FMT("bzr update -r ~s", [Rev]), [{cd, AppDir}]);
update_source1(AppDir, {rsync, Url}) ->
    rebar_utils:sh(?FMT("rsync -az --delete ~s/ ~s",[Url,AppDir]),[]).

%% ===================================================================
%% Source helper functions
%% ===================================================================

source_engine_avail(Source) ->
    Name = element(1, Source),
    source_engine_avail(Name, Source).

source_engine_avail(Name, Source)
  when Name == hg; Name == git; Name == svn; Name == bzr; Name == rsync ->
    case vcs_client_vsn(Name) >= required_vcs_client_vsn(Name) of
        true ->
            true;
        false ->
            ?ABORT("Rebar requires version ~p or higher of ~s to process ~p\n",
                   [required_vcs_client_vsn(Name), Name, Source])
    end.

vcs_client_vsn(false, _VsnArg, _VsnRegex) ->
    false;
vcs_client_vsn(Path, VsnArg, VsnRegex) ->
    {ok, Info} = rebar_utils:sh(Path ++ VsnArg, [{env, [{"LANG", "C"}]},
                                                 {use_stdout, false}]),
    case re:run(Info, VsnRegex, [{capture, all_but_first, list}]) of
        {match, Match} ->
            list_to_tuple([list_to_integer(S) || S <- Match]);
        _ ->
            false
    end.

required_vcs_client_vsn(hg)    -> {1, 1};
required_vcs_client_vsn(git)   -> {1, 5};
required_vcs_client_vsn(bzr)   -> {2, 0};
required_vcs_client_vsn(svn)   -> {1, 6};
required_vcs_client_vsn(rsync) -> {2, 0}.

vcs_client_vsn(hg) ->
    vcs_client_vsn(rebar_utils:find_executable("hg"), " --version",
                   "version (\\d+).(\\d+)");
vcs_client_vsn(git) ->
    vcs_client_vsn(rebar_utils:find_executable("git"), " --version",
                   "git version (\\d+).(\\d+)");
vcs_client_vsn(bzr) ->
    vcs_client_vsn(rebar_utils:find_executable("bzr"), " --version",
                   "Bazaar \\(bzr\\) (\\d+).(\\d+)");
vcs_client_vsn(svn) ->
    vcs_client_vsn(rebar_utils:find_executable("svn"), " --version",
                   "svn, version (\\d+).(\\d+)");
vcs_client_vsn(rsync) ->
    vcs_client_vsn(rebar_utils:find_executable("rsync"), " --version",
                   "rsync  version (\\d+).(\\d+)").

has_vcs_dir(git, Dir) ->
    filelib:is_dir(filename:join(Dir, ".git"));
has_vcs_dir(hg, Dir) ->
    filelib:is_dir(filename:join(Dir, ".hg"));
has_vcs_dir(bzr, Dir) ->
    filelib:is_dir(filename:join(Dir, ".bzr"));
has_vcs_dir(svn, Dir) ->
    filelib:is_dir(filename:join(Dir, ".svn"))
        orelse filelib:is_dir(filename:join(Dir, "_svn"));
has_vcs_dir(rsync, _) ->
    true;
has_vcs_dir(_, _) ->
    true.

print_source(#dep{app=App, source=Source}) ->
    ?CONSOLE("~s~n", [format_source(App, Source)]).

format_source(App, {git, Url}) ->
    ?FMT("~p BRANCH ~s ~s", [App, "HEAD", Url]);
format_source(App, {git, Url, ""}) ->
    ?FMT("~p BRANCH ~s ~s", [App, "HEAD", Url]);
format_source(App, {git, Url, {branch, Branch}}) ->
    ?FMT("~p BRANCH ~s ~s", [App, Branch, Url]);
format_source(App, {git, Url, {tag, Tag}}) ->
    ?FMT("~p TAG ~s ~s", [App, Tag, Url]);
format_source(App, {_, Url, Rev}) ->
    ?FMT("~p REV ~s ~s", [App, Rev, Url]);
format_source(App, undefined) ->
    ?FMT("~p", [App]).