$ git clone -n https://src.fedoraproject.org/rpms/fast-cdr.git /var/lib/mock/f45-build-8676-393/root/chroot_tmpdir/scmroot/fast-cdr
Cloning into '/var/lib/mock/f45-build-8676-393/root/chroot_tmpdir/scmroot/fast-cdr'...
$ git fetch origin 70610b1ac6afd2c493953e9cc6a5e0bdf8e6be4c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fast-cdr
 * [new ref]         70610b1ac6afd2c493953e9cc6a5e0bdf8e6be4c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 70610b1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild