Anyone having a problem with Drush 7 and Drupal 8 alpha-11 On a Linux system I installed Drush with Composer and when I try to use it with Drupal 8 alpha-11 I get this error. I looked around but can't find anything about it.

$ drush st

PHP Fatal error:  Class 'Drupal\Core\Site\Settings' not found in /home/$USER/.composer/vendor/drush/drush/commands/core/drupal/environment.inc on line 278
Fatal error: Class 'Drupal\Core\Site\Settings' not found in /home/$USER/.composer/vendor/drush/drush/commands/core/drupal/environment.inc on line 278
Drush command terminated abnormally due to an unrecoverable error.                                                                                                                                                                [error]
Error: Class 'Drupal\Core\Site\Settings' not found in /home/$USER/.composer/vendor/drush/drush/commands/core/drupal/environment.inc, line 278
I found the same issue. Upgrading Drupal 8 to the latest change (8.x branch instead of the alpha11 version) Drush works properly.