$ git clone -n https://src.fedoraproject.org/rpms/kgamma.git /var/lib/mock/f41-build-855898-167429/root/chroot_tmpdir/scmroot/kgamma
Cloning into '/var/lib/mock/f41-build-855898-167429/root/chroot_tmpdir/scmroot/kgamma'...
$ git fetch origin 7c21487294a19195867f3db1ccb6313485a39670:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kgamma
 * [new ref]         7c21487294a19195867f3db1ccb6313485a39670 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7c21487 6.2.1