1 files changed, 28 insertions, 5 deletions
diff --git a/src/rcl_prv_discover.erl b/src/rcl_prv_discover.erl
index 82f138b..0a12d24 100644
--- a/src/rcl_prv_discover.erl
+++ b/src/rcl_prv_discover.erl
@@ -64,11 +64,13 @@ resolve_app_metadata(State, LibDirs, OutputDir) ->
                                                discover_dir([OutputDir],
                                                             LibDir)
                                            end, LibDirs)),
+    AppMeta1 = setup_overrides(State, AppMeta0),
+
     Errors = [case El of
                   {error, Ret} -> Ret;
                   _ -> El
               end
-              || El <- AppMeta0,
+              || El <- AppMeta1,
                  case El of
                      {error, _} ->
                          true;
@@ -78,17 +80,35 @@ resolve_app_metadata(State, LibDirs, OutputDir) ->
 
     case Errors of
         [] ->
-            AppMeta1 = lists:flatten(AppMeta0),
+            AppMeta2 = lists:flatten(AppMeta1),
             rcl_log:debug(rcl_state:log(State),
                           fun() ->
                                   ["Resolved the following OTP Applications from the system: \n",
-                                   [[rcl_app_info:format(1, App), "\n"] || App <- AppMeta1]]
+                                   [[rcl_app_info:format(1, App), "\n"] || App <- AppMeta2]]
                           end),
-            {ok, rcl_state:available_apps(State, AppMeta1)};
+            {ok, rcl_state:available_apps(State, AppMeta2)};
         _ ->
             ?RCL_ERROR(Errors)
     end.
 
+app_name({error, _}) ->
+    undefined;
+app_name(AppMeta) ->
+    rcl_app_info:name(AppMeta).
+
+setup_overrides(State, AppMetas0) ->
+    Overrides = rcl_state:overrides(State),
+    AppMetas1 = [AppMeta || AppMeta <- AppMetas0,
+                            not lists:keymember(app_name(AppMeta), 1, Overrides)],
+    [case is_valid_otp_app(filename:join([FileName, "ebin",
+                                         erlang:atom_to_list(AppName) ++ ".app"])) of
+         [] ->
+             {error, {invalid_override, AppName, FileName}};
+         Error = {error, _} ->
+             Error;
+         App ->
+             rcl_app_info:link(App, true)
+     end || {AppName, FileName} <- Overrides] ++ AppMetas1.
 
 get_lib_dirs(State) ->
     LibDirs0 = rcl_state:lib_dirs(State),
@@ -133,6 +153,9 @@ add_system_lib_dir(State, LibDirs) ->
     end.
 
 -spec format_detail(ErrorDetail::term()) -> iolist().
+format_detail({error, {invalid_override, AppName, FileName}}) ->
+    io_lib:format("Override {~p, ~p} is not a valid OTP App. Perhaps you forgot to build it?",
+                  [AppName, FileName]);
 format_detail({accessing, File, eaccess}) ->
     io_lib:format("permission denied accessing file ~s", [File]);
 format_detail({accessing, File, Type}) ->
@@ -172,7 +195,7 @@ discover_dir(IgnoreDirs, File) ->
             is_valid_otp_app(File)
     end.
 
--spec is_valid_otp_app(file:name()) -> [rcl_app_info:t() | {error, Reason::term()} | []].
+-spec is_valid_otp_app(file:name()) -> rcl_app_info:t() | {error, Reason::term()} | [].
 is_valid_otp_app(File) ->
     %% Is this an ebin dir?
     EbinDir = filename:dirname(File),