copy all files from ebin to build output ebin if exists

src/rebar_prv_compile.erl

@@ -71,7 +71,7 @@ build_app(State, AppInfo) ->
     AppDir = rebar_app_info:dir(AppInfo),
     OutDir = rebar_app_info:out_dir(AppInfo),
 
-    copy_app_dirs(rebar_app_info:name(AppInfo), AppDir, OutDir),
+    copy_app_dirs(AppDir, OutDir),
 
     S = case rebar_app_info:state(AppInfo) of
             undefined ->
@@ -108,16 +108,17 @@ handle_args(State) ->
     Jobs = proplists:get_value(jobs, Args, ?DEFAULT_JOBS),
     {ok, rebar_state:set(State, jobs, Jobs)}.
 
-copy_app_dirs(AppName, OldAppDir, AppDir) ->
+copy_app_dirs(OldAppDir, AppDir) ->
     case ec_cnv:to_binary(filename:absname(OldAppDir)) =/=
         ec_cnv:to_binary(filename:absname(AppDir)) of
         true ->
-            Name = ec_cnv:to_list(AppName),
-            AppFile = filename:join([OldAppDir, "ebin", Name++".app"]),
-            case filelib:is_file(AppFile) of
+            EbinDir = filename:join([OldAppDir, "ebin"]),
+            %% copy all files from ebin if it exists
+            case filelib:is_dir(EbinDir) of
                 true ->
-                    file:copy(AppFile,
-                              filename:join([AppDir, "ebin", Name++".app"]));
+                    OutEbin = filename:join(AppDir, "ebin"),
+                    filelib:ensure_dir(filename:join(OutEbin, "dummy.beam")),
+                    rebar_file_utils:cp_r(filelib:wildcard(filename:join(EbinDir, "*")), OutEbin);
                 false ->
                     ok
             end,