$ git clone -n https://src.fedoraproject.org/rpms/reposurgeon.git /var/lib/mock/f42-build-866811-174151/root/chroot_tmpdir/scmroot/reposurgeon
Cloning into '/var/lib/mock/f42-build-866811-174151/root/chroot_tmpdir/scmroot/reposurgeon'...
$ git fetch origin 4392b2aa365da7e7ab07d3e44ae07d01c4c2f16d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/reposurgeon
 * [new ref]         4392b2aa365da7e7ab07d3e44ae07d01c4c2f16d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4392b2a reposurgeon: 5.2 release