$ git clone -n https://src.fedoraproject.org/rpms/ghc-tagged.git /var/lib/mock/f41-build-837887-159471/root/chroot_tmpdir/scmroot/ghc-tagged
Cloning into '/var/lib/mock/f41-build-837887-159471/root/chroot_tmpdir/scmroot/ghc-tagged'...
$ git fetch origin 5014904263da2be8522286aa4d5b99b89173a8ad:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-tagged
 * [new ref]         5014904263da2be8522286aa4d5b99b89173a8ad -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5014904 https://hackage.haskell.org/package/tagged-0.8.8/changelog