$ git clone -n https://github.com/xcp-ng-rpms/xen.git /var/lib/mock/v8.3-u-ydi2-7842-22501/root/chroot_tmpdir/scmroot/xen
Cloning into '/var/lib/mock/v8.3-u-ydi2-7842-22501/root/chroot_tmpdir/scmroot/xen'...
$ git reset --hard 6e38771dc1ff1bfaa86fc4bb8eafe300cae5ad1a
fatal: Could not parse object '6e38771dc1ff1bfaa86fc4bb8eafe300cae5ad1a'.