$ git clone -n https://src.fedoraproject.org/rpms/ceph.git /var/lib/mock/f41-build-side-1-2749831-31008/root/chroot_tmpdir/scmroot/ceph
Cloning into '/var/lib/mock/f41-build-side-1-2749831-31008/root/chroot_tmpdir/scmroot/ceph'...
remote: warning: refname 'HEAD' is ambiguous.        
$ git fetch origin 3cf60da63e445bace5a4dac5bb4db2a90ce6d940:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ceph
 * [new ref]         3cf60da63e445bace5a4dac5bb4db2a90ce6d940 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3cf60da ceph-19.2.0 GA