$ git clone -n https://src.fedoraproject.org/rpms/python-cobalt.git /var/lib/mock/f45-build-29957-642/root/chroot_tmpdir/scmroot/python-cobalt
Cloning into '/var/lib/mock/f45-build-29957-642/root/chroot_tmpdir/scmroot/python-cobalt'...
$ git fetch origin 8a6b58702bca967f685a11e68649b66a22f773f8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-cobalt
 * [new ref]         8a6b58702bca967f685a11e68649b66a22f773f8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8a6b587 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild