$ git clone -n https://src.fedoraproject.org/rpms/ghc-data-reify.git /var/lib/mock/f41-build-839410-160145/root/chroot_tmpdir/scmroot/ghc-data-reify
Cloning into '/var/lib/mock/f41-build-839410-160145/root/chroot_tmpdir/scmroot/ghc-data-reify'...
$ git fetch origin 16f8191ec812b53da35192de35a3f34ae9330b18:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-data-reify
 * [new ref]         16f8191ec812b53da35192de35a3f34ae9330b18 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 16f8191 refresh .cabal revision