$ git clone -n https://src.fedoraproject.org/rpms/ghc-erf.git /var/lib/mock/f41-build-side-1-2636674-26251/root/chroot_tmpdir/scmroot/ghc-erf
Cloning into '/var/lib/mock/f41-build-side-1-2636674-26251/root/chroot_tmpdir/scmroot/ghc-erf'...
$ git fetch origin 9a78944bc8ad0913f600f1ad597715f06cdc99ed:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-erf
 * [new ref]         9a78944bc8ad0913f600f1ad597715f06cdc99ed -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9a78944 bump release