$ git clone -n https://src.fedoraproject.org/rpms/ghc-STMonadTrans.git /var/lib/mock/f41-build-839484-160201/root/chroot_tmpdir/scmroot/ghc-STMonadTrans
Cloning into '/var/lib/mock/f41-build-839484-160201/root/chroot_tmpdir/scmroot/ghc-STMonadTrans'...
$ git fetch origin b70646b3c17d1e114d818c1d55d2c447fee88467:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-STMonadTrans
 * [new ref]         b70646b3c17d1e114d818c1d55d2c447fee88467 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b70646b https://hackage.haskell.org/package/STMonadTrans-0.4.8/changelog