$ git clone -n https://src.fedoraproject.org/rpms/xapps.git /var/lib/mock/f41-build-814641-149002/root/chroot_tmpdir/scmroot/xapps
Cloning into '/var/lib/mock/f41-build-814641-149002/root/chroot_tmpdir/scmroot/xapps'...
$ git fetch origin 8090d24e54c3526e89feda7e11ee20500ddb525d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xapps
 * [new ref]         8090d24e54c3526e89feda7e11ee20500ddb525d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8090d24 Update to 2.8.4