$ git clone -n https://src.fedoraproject.org/rpms/ghc-reflection.git /var/lib/mock/f41-build-839427-160145/root/chroot_tmpdir/scmroot/ghc-reflection
Cloning into '/var/lib/mock/f41-build-839427-160145/root/chroot_tmpdir/scmroot/ghc-reflection'...
$ git fetch origin f864b8fa7e842be559d9f63a1e19b0b215a1632d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-reflection
 * [new ref]         f864b8fa7e842be559d9f63a1e19b0b215a1632d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f864b8f https://hackage.haskell.org/package/reflection-2.1.8/changelog