Regression: Drush 13.3 does not properly handle SIGQUIT signal

[Chi-teck]

That apparently is caused by #6124.

Here is example of a simple long running Drush command

#[AsCommand( 'example')]
final class ExampleCommand extends Command implements SignalableCommandInterface {

  /**
   * Signal flag.
   */
  private bool $stop = FALSE;


  /**
   * {@inheritdoc}
   */
  protected function execute(InputInterface $input, OutputInterface $output): int {
    for ($i = 1; $i <= 60; $i++, sleep(1)) {
      echo '.';
      if ($this->stop) {
        echo 'Signal received...', \PHP_EOL;
        sleep(5);
        echo 'Done!', \PHP_EOL;
        break;
      }
    }
    return 0;
  }

  /**
   * {@inheritdoc}
   */
  public function getSubscribedSignals(): array {
    return [\SIGTERM, \SIGQUIT, \SIGINT];
  }

  /**
   * {@inheritdoc}
   */
  public function handleSignal(int $signal): false|int {
    $this->stop = TRUE;
    return FALSE;
  }

}

Start the above command and send SIGQUIT (Ctrl + \) to it.

Output Drush 13.2 (correct)

$ ./vendor/bin/drush example
....^\.Signal received!
Done!

Output Drush 13.3 (wrong)

$ ./vendor/bin/drush example
....^\.Signal received!
Quit (core dumped)
$ Done!

Note that in the last example "Done!" appears when Drush was already terminated. If a command is managed through some process manager, i.e. Supervisor, such behavior causes orphan processes.

[Chi-teck]

The new way to launch Drush creates two additional shell processes besides the PHP. Also some people reported that Drush 13.3 is not working on Windows because of this change.

[webflo]

@Chi-teck Could you try to run ./vendor/drush/drush/drush.php directly? Just to make sure, this executable has the correct behaviour?

[Chi-teck]

Yes, drush.php works correctly.

$ ./vendor/bin/drush example
.....^\.Signal received...
Quit (core dumped)
$ Done!

$ ./vendor/drush/drush/drush.php example
.....^\.Signal received...
Done!

[webflo]

In the original PR I implemented it without exec, because the Composer Wrapper script also works this way.

https://github.com/composer/composer/blob/main/src/Composer/Installer/BinaryInstaller.php#L409