Symfony web debug tool bar disappears when using sfNoLogger

Question

Why does the web debug tool bar disappear when I use sfNoLogger in the factories.yml:

dev:
  logger:
    class:   sfNoLogger
    param:
      level:   err
      loggers: ~

When I remove these lines the tool bar appears.

Answer 1

Because the sf*No*Logger does not log anything. It's usually used for production.