I’ve been using Rails Edge on a project for no particular reason. Today I did an svn update and things stopped working.

A secret is required to generate an integrity hash for cookie session data. Use config.action_controller.session = { :secret => “some secret phrase” } in config/environment.rb

No problem – I followed those instructions and added the option to config/environment.rb. Then I got another problem.

ArgumentError (`name’ required):
/vendor/rails/actionpack/lib/action_controller/cgi_ext/cookie_performance_fix.rb:44:in `initialize’
/vendor/rails/actionpack/lib/action_controller/session/cookie_store.rb:129:in `write_cookie’

All I could find was this post. The resolution was to update everything, create a new project, and copy code in. I couldn’t be bothered with this, so I unfroze and went to gem rails (1.2.2). Now neither Mongrel or Webrick will start.

/opt/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/initializer.rb:328:in `send’: undefined method `session=’ for ActionController::Base:Class (NoMethodError)

Aaargh! I googled for the exception and found nothing. Eventually I check out initializer.rb and realise what’s happening. From config/environment.rb I remove

config.action_controller.session = { :secret => “some secret phrase” }

Problem gone.

Lessons? When I give up on one way of fixing a problem, completely back out of that fix before trying another.