dev-libs/gobject-introspection installs Python modules into /usr/lib64/gobject-introspection instead of implementation-specific directories. This makes implementation dependencies incorrect and breaks byte-compiling of Python modules. Please modify the ebuild to install files into directory specified as $(python_get_sitedir).
Well, I've taken a second look at this and it seems that this is not necessarily wrong. Considering that the modules are supposedly used by g-ir-scanner only and never imported directly by other packages, I would say that external dir is fine and hasufell just caused unnecessary confusion. In any case, I'm fine with either way. If you'd like to change the install location, it would be as simple as using: src_install() { gnome2_src_install \ pkgpyexecdir="$(python_get_sitedir)"/giscanner
We are just following a deliberate upstream decision; they don't want to "encourage pollution of the global namespace for internal components", which presumably means they regard the contents of /usr/lib64/gobject-introspection as private modules that third party code should never import. See https://bugzilla.gnome.org/show_bug.cgi?id=574501 If you think this is wrong, please file an upstream bug and convince them :)