$ git clone -n https://src.fedoraproject.org/rpms/ghc-extra.git /var/lib/mock/f33-build-139322-42339/root/chroot_tmpdir/scmroot/ghc-extra
Cloning into '/var/lib/mock/f33-build-139322-42339/root/chroot_tmpdir/scmroot/ghc-extra'...
$ git reset --hard 851d99fd1d02d0f17049e48a70e83525f91bd258
HEAD is now at 851d99f update to 1.6.18