$ git clone -n https://src.fedoraproject.org/rpms/bomber.git /var/lib/mock/f39-build-1544993-36675/root/chroot_tmpdir/scmroot/bomber
Cloning into '/var/lib/mock/f39-build-1544993-36675/root/chroot_tmpdir/scmroot/bomber'...
$ git fetch origin cf454c7a43ef723e76503639a5cf171e23cb67d0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bomber
 * [new ref]         cf454c7a43ef723e76503639a5cf171e23cb67d0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cf454c7 23.08.2