If you are outside fixtures, then LoadErrors are meaningful, e.g. in script/console
>> AccountController
MissingSourceFile: no such file to load -- hpricot_scan
The same issue blows up cryptically in fixtures, e.g.
LoadError: Expected account_controller.rb to define AccountController
The problem is that fixture loading swallows LoadErrors in silence. The comments seem to indicate that this behavior is necessary in some circumstances. As a band-aid, I have written a patch that at least logs the error.
If somebody has better understanding of when swallowing LoadErrors is appropriate, this patch could be improved to swallow the ok ones and raise the bad ones. I'd be happy to help.
The patch is tested, but the tests are ugly. Better tests would drive a more significant code change, but I didn't want this patch to get caught up in broader issues. If somebody wants to go down this road I will help.