$ git clone -n https://src.fedoraproject.org/rpms/ghc-temporary.git /var/lib/mock/f31-build-54989-28076/root/chroot_tmpdir/scmroot/ghc-temporary
Cloning into '/var/lib/mock/f31-build-54989-28076/root/chroot_tmpdir/scmroot/ghc-temporary'...
$ git reset --hard 2c64c624e2f65a4191418209a1eaa09d718ca7bf
HEAD is now at 2c64c62 update to 1.3