$ git clone -n https://src.fedoraproject.org/rpms/gt5.git /var/lib/mock/f45-build-13137-446/root/chroot_tmpdir/scmroot/gt5
Cloning into '/var/lib/mock/f45-build-13137-446/root/chroot_tmpdir/scmroot/gt5'...
$ git fetch origin 53152c4e14f2dd235c7ebd9aeda5c07f4850fc7e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gt5
 * [new ref]         53152c4e14f2dd235c7ebd9aeda5c07f4850fc7e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 53152c4 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild