$ git clone -n https://src.fedoraproject.org/rpms/ghc-base64.git /var/lib/mock/f45-build-10010-412/root/chroot_tmpdir/scmroot/ghc-base64
Cloning into '/var/lib/mock/f45-build-10010-412/root/chroot_tmpdir/scmroot/ghc-base64'...
$ git fetch origin a6317974ad6afee23e4e750f4f697ba33130977a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-base64
 * [new ref]         a6317974ad6afee23e4e750f4f697ba33130977a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a631797 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild