$ git clone -n https://github.com/xcp-ng-rpms/xcp-ng-xapi-plugins.git /var/lib/mock/v8.3-incoming-9472-28212/root/chroot_tmpdir/scmroot/xcp-ng-xapi-plugins
Cloning into '/var/lib/mock/v8.3-incoming-9472-28212/root/chroot_tmpdir/scmroot/xcp-ng-xapi-plugins'...
$ git fetch origin 12c8448cce0154c059fe0d229e8573f3869cb6f9:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xcp-ng-xapi-plugins
 * [new ref]         12c8448cce0154c059fe0d229e8573f3869cb6f9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 12c8448 Update to 1.15.0