$ git clone -n https://github.com/xcp-ng-rpms/xcp-ng-release /var/lib/mock/v9.0-u-ydi1-11157-29572/root/chroot_tmpdir/scmroot/xcp-ng-release
Cloning into '/var/lib/mock/v9.0-u-ydi1-11157-29572/root/chroot_tmpdir/scmroot/xcp-ng-release'...
$ git fetch origin 5cfdbb6be652fe2b867f12b73862268be53a4c52:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xcp-ng-release
 * [new ref]         5cfdbb6be652fe2b867f12b73862268be53a4c52 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5cfdbb6 bump release for test build