When trying to start up a newly created Rails 3 (beta) application, I get an error with the mongo gem loaded on the system.

It appears the bundler gem is scanning the *.gemspec files in the system gems and evaluating the Gem::Specification therein. When it gets to mongo and mongo_ext there is code that assumes mongo is is in the load path (requre 'lib/mongo') and how the file is being loaded (VERSION_HEADER = File.open(File.join(File.dirname(_FILE_), 'ext', 'cbson', 'version.h'), "r")).

I don't think this necessarily goes against Gem specification, but mongo is the only gem that I have seen that programatically specifies attributes in the gemspec versus having them generated via a rake task.