Catch package not found exceptions when running bundle command

[c9s]

PHP Notice:  Undefined index: CascadingAttribute in phar:///opt/local/bin/onion.phar/Onion/Pear/Channel.php on line 2
PHP Stack trace:
PHP   1. {main}() /opt/local/bin/onion.phar:0
PHP   2. require() /opt/local/bin/onion.phar:6
PHP   3. CLIFramework\Application->run() phar:///opt/local/bin/onion.phar/scripts/onion.embed:2
PHP   4. Onion\Command\BundleCommand->execute() phar:///opt/local/bin/onion.phar/CLIFramework/Application.php:2
PHP   5. Onion\Dependency\DependencyResolver->resolve() phar:///opt/local/bin/onion.phar/Onion/Command/BundleCommand.php:2
PHP   6. Onion\Pear\Channel->getPackage() phar:///opt/local/bin/onion.phar/Onion/Dependency/DependencyResolver.php:2

Notice: Undefined index: CascadingAttribute in phar:///opt/local/bin/onion.phar/Onion/Pear/Channel.php on line 2