$ git clone -n https://src.fedoraproject.org/rpms/ghc-cborg.git /var/lib/mock/f41-build-837930-159471/root/chroot_tmpdir/scmroot/ghc-cborg
Cloning into '/var/lib/mock/f41-build-837930-159471/root/chroot_tmpdir/scmroot/ghc-cborg'...
$ git fetch origin 4d719d3d50a6394a4c2bdf8181160dd310e3b9d8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-cborg
 * [new ref]         4d719d3d50a6394a4c2bdf8181160dd310e3b9d8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4d719d3 https://hackage.haskell.org/package/cborg-0.2.10.0/changelog