$ git clone -n https://src.fedoraproject.org/rpms/ballerburg.git /var/lib/mock/f42-build-side-1-3505995-45995/root/chroot_tmpdir/scmroot/ballerburg
Cloning into '/var/lib/mock/f42-build-side-1-3505995-45995/root/chroot_tmpdir/scmroot/ballerburg'...
$ git fetch origin 3152fc8807292c4dadddded9dba1e968a88ecc70:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ballerburg
 * [new ref]         3152fc8807292c4dadddded9dba1e968a88ecc70 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3152fc8 Updated to new upstream release