$ git clone -n https://src.fedoraproject.org/rpms/xsetroot.git /var/lib/mock/f45-build-39145-732/root/chroot_tmpdir/scmroot/xsetroot
Cloning into '/var/lib/mock/f45-build-39145-732/root/chroot_tmpdir/scmroot/xsetroot'...
$ git fetch origin 31bfed154677bcb14cec59c8f1d7af127eb5baae:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xsetroot
 * [new ref]         31bfed154677bcb14cec59c8f1d7af127eb5baae -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 31bfed1 opt-in to packit for rawhide