Missing helper file error after Rails3 conversion

I'm in the midst of converting an old Rails2.3 project to 3, and I'm running into this runtime error when I load the first page:

Missing helper file helpers/activesuppo开发者_开发知识库rt.rb

Full stacktrace here

Has anyone else run into this? Looks like something changed in how helpers are loaded, but I don't see any obvious solutions.

I was able to work around the problem by created an empty file at app/helpers/activesupport.rb but I would like to know why this is happening in the first place.

Could it be a clash with ActiveSupport?

I am not sure why its even looking for such a helper - do you have a model or controller called activesupport?

I was having a similar issue with Hpricot. I had a require 'hpricot' statement in a helper, but I didn't have Hpricot in my Gemfile.

In your case, if you were explicitly requiring ActiveSupport somewhere, you would have to add it to your Gemfile (I just tried it and despite having Rails in my Gemfile, I still got the same error you were getting).