Use format_reason in supervisor child exit messages, too

src/error_logger_lager_h.erl

@@ -90,7 +90,7 @@ handle_event(Event, State) ->
             case lists:sort(D) of
                 [{errorContext, Ctx}, {offender, Off}, {reason, Reason}, {supervisor, Name}] ->
                     Offender = format_offender(Off),
-                    ?LOG(error, Pid, "Supervisor ~w had child ~s exit with reason ~w in context ~w", [element(2, Name), Offender, Reason, Ctx]);
+                    ?LOG(error, Pid, "Supervisor ~w had child ~s exit with reason ~s in context ~w", [element(2, Name), Offender, format_reason(Reason), Ctx]);
                 _ ->
                     ?LOG(error, Pid, ["SUPERVISOR REPORT ", print_silly_list(D)])
             end;

test/lager_test_backend.erl

@@ -479,6 +479,16 @@ error_logger_redirect_test_() ->
                         ?assertEqual(Expected, lists:flatten(Msg))
                 end
             },
+            {"supervisor reports with real error",
+                fun() ->
+                        error_logger:error_report(supervisor_report, [{errorContext, france}, {offender, [{name, mini_steve}, {mfargs, {a, b, [c]}}, {pid, bleh}]}, {reason, {function_clause,[{crash,handle_info,[foo]}]}}, {supervisor, {local, steve}}]),
+                        timer:sleep(100),
+                        {_, _, Msg} = pop(),
+                        Expected = lists:flatten(io_lib:format("[error] ~w Supervisor steve had child mini_steve started with a:b(c) at bleh exit with reason no function clause matching crash:handle_info(foo) in context france", [self()])),
+                        ?assertEqual(Expected, lists:flatten(Msg))
+                end
+            },
+
             {"supervisor_bridge reports",
                 fun() ->
                         error_logger:error_report(supervisor_report, [{errorContext, france}, {offender, [{mod, mini_steve}, {pid, bleh}]}, {reason, fired}, {supervisor, {local, steve}}]),