$ git clone -n https://src.fedoraproject.org/rpms/ghc-lukko.git /var/lib/mock/f41-build-837642-159296/root/chroot_tmpdir/scmroot/ghc-lukko
Cloning into '/var/lib/mock/f41-build-837642-159296/root/chroot_tmpdir/scmroot/ghc-lukko'...
$ git fetch origin c732d99f140960cfc556b1add9d7b77ac5e0fff9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-lukko
 * [new ref]         c732d99f140960cfc556b1add9d7b77ac5e0fff9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c732d99 refresh .cabal revision