$ git clone -n https://src.fedoraproject.org/rpms/pebble.git /var/lib/mock/f45-build-21520-586/root/chroot_tmpdir/scmroot/pebble
Cloning into '/var/lib/mock/f45-build-21520-586/root/chroot_tmpdir/scmroot/pebble'...
$ git fetch origin 46bb6bb6242191d7ea29b4b79887645472dc4da6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pebble
 * [new ref]         46bb6bb6242191d7ea29b4b79887645472dc4da6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 46bb6bb Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild