$ git clone -n https://github.com/xcp-ng-rpms/xs-opam-src.git /var/lib/mock/v8.3-base-3912-3845/root/chroot_tmpdir/scmroot/xs-opam-src
Cloning into '/var/lib/mock/v8.3-base-3912-3845/root/chroot_tmpdir/scmroot/xs-opam-src'...
$ git reset --hard 438174db9defc01551f6108fece0e839c4ba5999
HEAD is now at 438174d Rebuild for XCP-ng 8.3