$ git clone -n https://src.fedoraproject.org/rpms/btrfsmaintenance.git /var/lib/mock/f39-build-1489700-34501/root/chroot_tmpdir/scmroot/btrfsmaintenance
Cloning into '/var/lib/mock/f39-build-1489700-34501/root/chroot_tmpdir/scmroot/btrfsmaintenance'...
$ git fetch origin 2a68c2038fb85e196b046b98c3a6becf0ed81eb2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/btrfsmaintenance
 * [new ref]         2a68c2038fb85e196b046b98c3a6becf0ed81eb2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2a68c20 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild