$ git clone -n https://github.com/xcp-ng-rpms/xen.git /var/lib/mock/v8.2-u-tescande1-8853-27790/root/chroot_tmpdir/scmroot/xen
Cloning into '/var/lib/mock/v8.2-u-tescande1-8853-27790/root/chroot_tmpdir/scmroot/xen'...
$ git fetch origin a414a22b4718012b318265271f7150d832cb7bfd:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xen
 * [new ref]         a414a22b4718012b318265271f7150d832cb7bfd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a414a22 bump release for test build