The detection of the used compiler in dumper.py fails. Clang ends up as Microsoft compiler, which results in a build failure. After applying the patch in the URL, the package works.
+*gobject-introspection-1.36.0-r1 (05 Sep 2013)
+ 05 Sep 2013; Pacho Ramos <email@example.com>
+ Fix clang detection (#483412 by Stefan de Konink) and REQUIRED_USE (#471440 by
+ Jonathan Callen)
*** Bug 497492 has been marked as a duplicate of this bug. ***