title: terminate called after throwing an instance of 'Poco::SystemException'
body: <p>Sometimes (about 1 out of 100 runs), my program terminates with this message:</p>
  
  <pre><code>terminate called after throwing an instance of 'Poco::SystemException'
    what():  System exception
  </code></pre>
  
  <p>my code is not the one catching the exception (all my catches are more verbose), and I am not sure where it's caught.
  it's very likely that the exception does contain a useful message, but it's not returned through the what() method but by the displayText() method.</p>
  
  <p>The string "terminate called after throwing an instance of" has ~600k in Google, so it's probably printed by code inserted by the compiler or by some common library (pthread?).
  I only seen this error message when the program ran on Linux (never on Windows).</p>
  
  <p>anyone knows in what code this uncaught exception is caught?</p>