protected function runBuildTask($sourceDir, $outputDir)
    {
        $buildTime = $this->runTimedTask(function () use ($sourceDir, $outputDir) {
            $this->builder->build($sourceDir, $outputDir);
        });

        $this->output->writeln(
            "<comment>PHP built in <time>{$buildTime}ms</time></comment>",
            OutputInterface::VERBOSITY_VERBOSE
        );
    }