$ git clone -n https://src.fedoraproject.org/rpms/ghc-yaml.git /var/lib/mock/f31-build-117101-34599/root/chroot_tmpdir/scmroot/ghc-yaml
Cloning into '/var/lib/mock/f31-build-117101-34599/root/chroot_tmpdir/scmroot/ghc-yaml'...
$ git reset --hard b1c97a6c82fc1a1c242aede99297603642431f20
HEAD is now at b1c97a6 enable system libyaml with patch