$ git clone -n https://github.com/xcp-ng-rpms/xen.git /var/lib/mock/v8.3-u-tescande1-4692-5068/root/chroot_tmpdir/scmroot/xen
Cloning into '/var/lib/mock/v8.3-u-tescande1-4692-5068/root/chroot_tmpdir/scmroot/xen'...
$ git reset --hard fa37a5efff8e1fc9d038a75b0551d32283a98b97
fatal: Could not parse object 'fa37a5efff8e1fc9d038a75b0551d32283a98b97'.