title: Symfony Process component returns exit code -1
body: <p>I am getting exit code -1 from the Symfony process command on some machines, while exactly the same code returns exit code 0 as excepted on others. In both cases the given command is executed successfully regarding its output.</p>
  
  <p>Running the same command line from shell gives the correct exit code (0).
  I produced a small test case to reproduce the issue:</p>
  
  <pre><code>use Symfony\Component\Process\Process;
  $process = new Process('./console');
  $process-&gt;run();
  echo $process-&gt;getExitCode();
  </code></pre>
  
  <p>Any ideas on how to diagnose this?</p>