$ git clone -n https://github.com/xcp-ng-rpms/xcp-ng-release.git /var/lib/mock/v8.3-u-stormi2-9492-28226/root/chroot_tmpdir/scmroot/xcp-ng-release
Cloning into '/var/lib/mock/v8.3-u-stormi2-9492-28226/root/chroot_tmpdir/scmroot/xcp-ng-release'...
$ git fetch origin e0b570826ce2d50df9f34b46d24342c387beb6d0:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xcp-ng-release
 * [new ref]         e0b570826ce2d50df9f34b46d24342c387beb6d0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e0b5708 bump release for test build