$ git clone -n https://src.fedoraproject.org/rpms/funionfs.git /var/lib/mock/f45-build-9335-401/root/chroot_tmpdir/scmroot/funionfs
Cloning into '/var/lib/mock/f45-build-9335-401/root/chroot_tmpdir/scmroot/funionfs'...
$ git fetch origin 086f0c605b46c138ff3219753692a74d8fe38d59:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/funionfs
 * [new ref]         086f0c605b46c138ff3219753692a74d8fe38d59 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 086f0c6 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild