$ git clone -n https://github.com/xcp-ng-rpms/varstored.git /var/lib/mock/v8.3-u-pcoval2-10426-28987/root/chroot_tmpdir/scmroot/varstored
Cloning into '/var/lib/mock/v8.3-u-pcoval2-10426-28987/root/chroot_tmpdir/scmroot/varstored'...
$ git fetch origin c3e9de0ec2e56741598cb543b2a05f85a6993d88:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/varstored
 * [new ref]         c3e9de0ec2e56741598cb543b2a05f85a6993d88 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c3e9de0 bump release for test build