public function packagePhpBuild($build_root)
    {
        $project_root = ProjectX::projectRoot();

        $stack = $this->taskFilesystemStack();
        if (file_exists("{$project_root}/patches")) {
            $stack->mirror("{$project_root}/patches", "{$build_root}/patches");
        }
        $stack->copy("{$project_root}/composer.json", "{$build_root}/composer.json");
        $stack->copy("{$project_root}/composer.lock", "{$build_root}/composer.lock");
        $stack->run();

        return $this;
    }