Errors do not bubble up...

[cwbeck]

try {
  throw new \Exception('Expect to see error caught');
} catch (\Throwable $t) {
  var_dump($t->getMessage());
}

But in your library...

$cmd = CMD::getInstance()->doNotTrapErrors();
try {
  $cmd->option('r')
    ->require()
    ->aka('run')
    ->describedAs('When set, use this title to address the person');
} catch (\Throwable $t) {
  var_dump('caught');
}

Never gets to that statement var_dump('caught');

Instead it just dumps out the error and dies...

PHP Fatal error:  Uncaught Exception: Required option r must be specified in /var/www/nano/vendor/nategood/commando/src/Commando/Command.php:466
Stack trace:
#0 /var/www/nano/vendor/nategood/commando/src/Commando/Command.php(164): Commando\Command->parse()
#1 [internal function]: Commando\Command->__destruct()
#2 {main}
  thrown in /var/www/nano/vendor/nategood/commando/src/Commando/Command.php on line 466

Fatal error: Uncaught Exception: Required option r must be specified in /var/www/nano/vendor/nategood/commando/src/Commando/Command.php on line 466

Exception: Required option r must be specified in /var/www/nano/vendor/nategood/commando/src/Commando/Command.php on line 466

Call Stack:
    0.0237     585528   1. Commando\Command->__destruct() /var/www/nano/vendor/nategood/commando/src/Commando/Command.php:0
    0.0237     585528   2. Commando\Command->parse() /var/www/nano/vendor/nategood/commando/src/Commando/Command.php:164
    0.0239     589064   3. Commando\Command->error() /var/www/nano/vendor/nategood/commando/src/Commando/Command.php:498

Too add:

   public function run(){
      if (!$this->parsed) {
          $this->parse();
      }
    }

    public function __destruct()
    {
        if (!$this->parsed) {
            $this->parse();
        }
    }

Created an identical function run(), when called (in sequence) the error is now caught properly. Is the a PHP issue whereby thrown \Exception after destruct? No idea...

try {
  $cmd = CMD::getInstance()->doNotTrapErrors();
  $cmd->option('r')
    ->require()
    ->aka('run')
    ->describedAs('When set, use this title to address the person')
    ->run();
} catch (\Throwable $t) {
  var_dump('now gets here when run() is used');
}

Fixed in #69

[NeoVance]

You can use the parse method, or move your try block around the the code where commando is being used, rather than where the command is being defined.

[mrcnpdlk]

PHP doc says: "Attempting to throw an exception from a destructor (called in the time of script termination) causes a fatal error."
So you cannot throw exception here. Of course You can, but dontcatch.

[NeoVance]

Right. If you don't explicitly run your Command, you can't catch the errors since validation wont happen until script termination. That is exactly how it works.