$ git clone -n https://src.fedoraproject.org/rpms/ghc-gi-harfbuzz.git /var/lib/mock/f41-build-1020903-18021/root/chroot_tmpdir/scmroot/ghc-gi-harfbuzz
Cloning into '/var/lib/mock/f41-build-1020903-18021/root/chroot_tmpdir/scmroot/ghc-gi-harfbuzz'...
$ git fetch origin 46eb8d1c9c8428f1d315f5ab71e681c451b529d2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-gi-harfbuzz
 * [new ref]         46eb8d1c9c8428f1d315f5ab71e681c451b529d2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 46eb8d1 refresh to cabal-rpm-2.1.5