$ git clone -n https://src.fedoraproject.org/rpms/xen.git /var/lib/mock/f37-build-672709-75506/root/chroot_tmpdir/scmroot/xen
Cloning into '/var/lib/mock/f37-build-672709-75506/root/chroot_tmpdir/scmroot/xen'...
$ git reset --hard 136d0a1506e43791ffe0752208799f626918130f
HEAD is now at 136d0a1 update to xen-4.16.2