$ git clone -n https://github.com/xcp-ng-rpms/xen.git /var/lib/mock/v8.1-testing-2118-1624/root/chroot_tmpdir/scmroot/xen
Cloning into '/var/lib/mock/v8.1-testing-2118-1624/root/chroot_tmpdir/scmroot/xen'...
$ git reset --hard 6625b6c04b3361236c61d3fc0572b05005e4bc4a
fatal: Could not parse object '6625b6c04b3361236c61d3fc0572b05005e4bc4a'.