$ git clone -n https://src.fedoraproject.org/rpms/ghc-lens-family-core.git /var/lib/mock/f41-build-837640-159296/root/chroot_tmpdir/scmroot/ghc-lens-family-core
Cloning into '/var/lib/mock/f41-build-837640-159296/root/chroot_tmpdir/scmroot/ghc-lens-family-core'...
$ git fetch origin e6fbfd75975c4c0f099c01075b53e5acbed07695:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-lens-family-core
 * [new ref]         e6fbfd75975c4c0f099c01075b53e5acbed07695 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e6fbfd7 https://hackage.haskell.org/package/lens-family-core-2.1.3/changelog