By default, gobject-introspection refers to libraries using their file name in the GIR file. Since we do not have FHS to reliably find libraries by their name, we are patching gobject-introspection to use absolute paths. This works fine for libraries installed to "$out/lib" but when a different path is used, the hard-coded absolute path will be incorrect. To deal with this case, we also patch Meson to be able to pass the install_dir to gobject-introspection. But it currently only passes the data for targets that have absolute install_dir set. To have correct libeog path, we therefore need to absolutize the install_dir.