$ git clone -n https://src.fedoraproject.org/rpms/gap-pkg-xmod.git /var/lib/mock/f40-build-2590841-62637/root/chroot_tmpdir/scmroot/gap-pkg-xmod
Cloning into '/var/lib/mock/f40-build-2590841-62637/root/chroot_tmpdir/scmroot/gap-pkg-xmod'...
$ git fetch origin 6a3caace1eeb95c268b484ccca5fe34e5860089b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gap-pkg-xmod
 * [new ref]         6a3caace1eeb95c268b484ccca5fe34e5860089b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6a3caac Rebuild for gap 4.13.0