Optimize list ops and error reporting in sh/2

src/rebar_utils.erl

@@ -102,8 +102,8 @@ sh(Command0, Options0) ->
     case sh_loop(Port, OutputHandler, []) of
         {ok, _Output} = Ok ->
             Ok;
-        {error, Rc} ->
-            ErrorHandler(Command, Rc)
+        {error, Err} ->
+            ErrorHandler(Command, Err)
     end.
 
 %% We need a bash shell to execute on windows
@@ -182,12 +182,12 @@ expand_code_path() ->
 
 expand_sh_flag(return_on_error) ->
     {error_handler,
-     fun(_Command, Rc) ->
-             {error, Rc}
+     fun(_Command, Err) ->
+             {error, Err}
      end};
 expand_sh_flag({abort_on_error, Message}) ->
     {error_handler,
-     fun(_Command, _Rc) ->
+     fun(_Command, _Err) ->
              ?ABORT(Message, [])
      end};
 expand_sh_flag(abort_on_error) ->
@@ -197,12 +197,12 @@ expand_sh_flag(use_stdout) ->
     {output_handler,
      fun(Line, Acc) ->
              ?CONSOLE("~s", [Line]),
-             [Acc | Line]
+             [Line | Acc]
      end};
 expand_sh_flag({use_stdout, false}) ->
     {output_handler,
      fun(Line, Acc) ->
-             [Acc | Line]
+             [Line | Acc]
      end};
 expand_sh_flag({cd, _CdArg} = Cd) ->
     {port_settings, Cd};
@@ -210,8 +210,8 @@ expand_sh_flag({env, _EnvArg} = Env) ->
     {port_settings, Env}.
 
 -spec log_and_abort(string(), integer()) -> no_return().
-log_and_abort(Command, Rc) ->
-    ?ABORT("~s failed with error: ~w\n", [Command, Rc]).
+log_and_abort(Command, {Rc, Output}) ->
+    ?ABORT("~s failed with error: ~w and output:~n~s~n", [Command, Rc, Output]).
 
 sh_loop(Port, Fun, Acc) ->
     receive
@@ -226,9 +226,9 @@ sh_loop(Port, Fun, Acc) ->
         {Port, {data, {noeol, Line}}} ->
             sh_loop(Port, Fun, Fun(Line, Acc));
         {Port, {exit_status, 0}} ->
-            {ok, lists:flatten(Acc)};
+            {ok, lists:flatten(lists:reverse(Acc))};
         {Port, {exit_status, Rc}} ->
-            {error, Rc}
+            {error, {Rc, lists:flatten(lists:reverse(Acc))}}
     end.
 
 beam_to_mod(Dir, Filename) ->