$ git clone -n https://src.fedoraproject.org/rpms/gamescope.git /var/lib/mock/f41-build-852770-166469/root/chroot_tmpdir/scmroot/gamescope
Cloning into '/var/lib/mock/f41-build-852770-166469/root/chroot_tmpdir/scmroot/gamescope'...
$ git fetch origin bf679d52b3ff9769529a9d4e2b6eec7588a1159e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gamescope
 * [new ref]         bf679d52b3ff9769529a9d4e2b6eec7588a1159e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bf679d5 Rebase to 3.15.9 (RHBZ#2309055)