Libgtkada source products two packages. Among them: libgtkadagl$(GTK_GL_ALI_VERSION)-dev libgtkada$(GTK_ALI_VERSIOn)-dev Currently, the former Depends: the latter (= common Debian binary version). Maybe the version restriction is not needed. Any binary package with the right GTK_ALI_VERSION should provide the exact same sources and ALI files. Is it safe to remove it?