$ git clone -n https://src.fedoraproject.org/rpms/ghc-managed.git /var/lib/mock/f45-build-10515-418/root/chroot_tmpdir/scmroot/ghc-managed
Cloning into '/var/lib/mock/f45-build-10515-418/root/chroot_tmpdir/scmroot/ghc-managed'...
$ git fetch origin cf78cdacc961b3844ea114d2fb7f19d280f0d0e0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-managed
 * [new ref]         cf78cdacc961b3844ea114d2fb7f19d280f0d0e0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cf78cda Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild