$ git clone -n https://src.fedoraproject.org/rpms/ceph.git /var/lib/mock/f42-build-861934-170512/root/chroot_tmpdir/scmroot/ceph
Cloning into '/var/lib/mock/f42-build-861934-170512/root/chroot_tmpdir/scmroot/ceph'...
remote: warning: refname 'HEAD' is ambiguous.        
$ git fetch origin 777309ac00b74213abd5a4212d0016a030a4ee46:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ceph
 * [new ref]         777309ac00b74213abd5a4212d0016a030a4ee46 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 777309a Rebuild for ICU 76