There are use case where one may want to specify --sourcedir option
multiple times to glib-compile-resources, which will look for
resources in every specified directory.
By doing this, we also need to get rid of the manual GResource XML
parsing and we opted to use the glib-compile-resources command with
the --generate-dependencies option. This command will solve the
multiple source_dir case for us.
Tim-Philipp Müller