$ git clone -n https://src.fedoraproject.org/rpms/ghc-bytes.git /var/lib/mock/f38-build-side-42-init-devel-1013177-29459/root/chroot_tmpdir/scmroot/ghc-bytes
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1013177-29459/root/chroot_tmpdir/scmroot/ghc-bytes'...
$ git fetch origin 77774cb9cc7b620f719dae4cf5d885b4c4cab908:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-bytes
 * [new ref]         77774cb9cc7b620f719dae4cf5d885b4c4cab908 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 77774cb update to 0.17.2