$ git clone -n https://src.fedoraproject.org/rpms/butt.git /var/lib/mock/f38-build-side-42-init-devel-1390764-30718/root/chroot_tmpdir/scmroot/butt
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1390764-30718/root/chroot_tmpdir/scmroot/butt'...
$ git fetch origin a67b27fa181b1848af8830dc5ed9195f77264674:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/butt
 * [new ref]         a67b27fa181b1848af8830dc5ed9195f77264674 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a67b27f Update to version 0.1.37, resolves rhbz#2156141