$ git clone -n https://src.fedoraproject.org/rpms/hexer.git /var/lib/mock/f45-build-13404-450/root/chroot_tmpdir/scmroot/hexer
Cloning into '/var/lib/mock/f45-build-13404-450/root/chroot_tmpdir/scmroot/hexer'...
$ git fetch origin 89cf63f76bdc37313541e90427b0be9fef610215:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/hexer
 * [new ref]         89cf63f76bdc37313541e90427b0be9fef610215 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 89cf63f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild