$ git clone -n https://github.com/xcp-ng-rpms/xcp-ng-release /var/lib/mock/v8.3-u-pcoval1-9734-28448/root/chroot_tmpdir/scmroot/xcp-ng-release
Cloning into '/var/lib/mock/v8.3-u-pcoval1-9734-28448/root/chroot_tmpdir/scmroot/xcp-ng-release'...
$ git fetch origin a2f3fa6fec91a17a5aff59545166000ed0399e90:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xcp-ng-release
 * [new ref]         a2f3fa6fec91a17a5aff59545166000ed0399e90 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a2f3fa6 bump release for test build