$ git clone -n https://src.fedoraproject.org/rpms/xgap.git /var/lib/mock/f31-build-60892-28794/root/chroot_tmpdir/scmroot/xgap
Cloning into '/var/lib/mock/f31-build-60892-28794/root/chroot_tmpdir/scmroot/xgap'...
$ git reset --hard 6d0d7d39e69e637f7b8c1db0eb784e6238f9695c
HEAD is now at 6d0d7d3 Require gap, not gap-core, so the binary can be invoked and the icon be seen.