$ git clone -n https://src.fedoraproject.org/rpms/realtime-tests.git /var/lib/mock/f45-build-34391-685/root/chroot_tmpdir/scmroot/realtime-tests
Cloning into '/var/lib/mock/f45-build-34391-685/root/chroot_tmpdir/scmroot/realtime-tests'...
$ git fetch origin 4c0a974bdef285ef08aeb2c88ec1b08ac453d0af:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/realtime-tests
 * [new ref]         4c0a974bdef285ef08aeb2c88ec1b08ac453d0af -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4c0a974 Rebase to upstream v2.11