$ git clone -n https://github.com/xcp-ng-rpms/guest-templates-json.git /var/lib/mock/v8.3-u-prebuild-9295-28065/root/chroot_tmpdir/scmroot/guest-templates-json
Cloning into '/var/lib/mock/v8.3-u-prebuild-9295-28065/root/chroot_tmpdir/scmroot/guest-templates-json'...
$ git fetch origin d930372c1851b7650d977f54c99e4023ca1e2095:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/guest-templates-json
 * [new ref]         d930372c1851b7650d977f54c99e4023ca1e2095 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d930372 bump release for test build