$ git clone -n https://github.com/xcp-ng-rpms/varstored.git /var/lib/mock/v8.3-u-prebuild-9296-28065/root/chroot_tmpdir/scmroot/varstored
Cloning into '/var/lib/mock/v8.3-u-prebuild-9296-28065/root/chroot_tmpdir/scmroot/varstored'...
$ git fetch origin 658369a7c631178e32a226d7aff0a771cfc150f8:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/varstored
 * [new ref]         658369a7c631178e32a226d7aff0a771cfc150f8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 658369a bump release for test build