$ git clone -n https://github.com/xcp-ng-rpms/trousers.git /var/lib/mock/v8.3-u-pcoval2-10023-28670/root/chroot_tmpdir/scmroot/trousers
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10023-28670/root/chroot_tmpdir/scmroot/trousers'...
$ git fetch origin 9c2fc4b0ac5c1d8d153350989479b8dd2fd63629:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/trousers
 * [new ref]         9c2fc4b0ac5c1d8d153350989479b8dd2fd63629 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9c2fc4b bump release for test build