$ git clone -n https://github.com/xcp-ng-rpms/xs-opam-src.git /var/lib/mock/v8.1-base-1727-1205/root/chroot_tmpdir/scmroot/xs-opam-src
Cloning into '/var/lib/mock/v8.1-base-1727-1205/root/chroot_tmpdir/scmroot/xs-opam-src'...
$ git reset --hard 75330a9eada3d98eb09071012c964b2d6f386a75
HEAD is now at 75330a9 Merge branch 'XS-8.1'