This one threw me for far too many minutes. In ActionView::Helpers::TextHelper the truncate method is broken for Ruby 1.8.7. I’m not exactly sure the version of ruby that it stopped working for, but I was previously on 1.8.6, and I don’t recall it not working. But after I upgraded to the latest patchlevel of 1.8.7, truncate stopped working.
Update 12/2/08: Fixed in Rails 2.2! (read more)
The error that I received was thus:
ActionView::TemplateError (undefined method `length' for #) on line #83 of dashboard/index.html.erb:
Fortunately, someone has submitted a ticket to Rails core. I hope it’s applied in the Rails 2.2.0 release.