Symfony 2 install problems

This is more here just in case any one else hits this error when trying to install Symfony.

PHP Fatal error:  Class 'appDevDebugProjectContainer' not found in app/bootstrap.php.cache on line 2441[](null)

Script Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::clearCache handling the post-install-cmd event terminated with an exception

Its due to that warning you totally ignored when installing composer.

curl -sS https://getcomposer.org/installer | php
#!/usr/bin/env php
Some settings on your machine may cause stability issues with Composer.
If you encounter issues, try to change the following:

The apc.enable_cli setting is incorrect.
Add the following to the end of your `php.ini`:
    apc.enable_cli = Off

The php.ini used by your command-line PHP is: /etc/php5/cli/php.ini If you can not modify the ini file, you can also run `php -d option=value` to modify ini values on the fly. You can use -d multiple times.

Downloading...

Make sure you set that apc.enable_cli value. Then all will be well.