Use infinite receive (thanks Hakan Mattsson)

src/rebar.erl

@@ -191,7 +191,9 @@ show_info_maybe_halt(O, Opts, F) ->
     case proplists:get_bool(O, Opts) of
         true ->
             F(),
-            halt(0);
+            halt(0),
+            %% workaround to delay exit until all output is written
+            receive after infinity -> ok end;
         false ->
             false
     end.
@@ -234,9 +236,7 @@ xref                                 Run cross reference analysis
 help                                 Show the program options
 version                              Show version information
 ">>,
-    io:put_chars(S),
-    %% workaround to delay exit until all output is written
-    timer:sleep(300).
+    io:put_chars(S).
 
 %%
 %% options accepted via getopt