$ git clone -n https://github.com/xcp-ng-rpms/xs-opam-src.git /var/lib/mock/v8.3-testing-4300-4361/root/chroot_tmpdir/scmroot/xs-opam-src
Cloning into '/var/lib/mock/v8.3-testing-4300-4361/root/chroot_tmpdir/scmroot/xs-opam-src'...
$ git reset --hard a6e08a206bb7df25ced22a93c44d517352f8b1ec
HEAD is now at a6e08a2 Merge branch 'XS-8.3'