/usr/local/lib/ruby/site_ruby/1.9.1/rubygems/source_index.rb:68:in `installed_spec_directories': undefined method `path' for Gem:Module (NoMethodError)
	from /usr/local/lib/ruby/site_ruby/1.9.1/rubygems/source_index.rb:58:in `from_installed_gems'
	from /usr/local/lib/ruby/site_ruby/1.9.1/rubygems.rb:883:in `source_index'
	from /usr/local/lib/ruby/site_ruby/1.9.1/rubygems/gem_path_searcher.rb:81:in `init_gemspecs'
	from /usr/local/lib/ruby/site_ruby/1.9.1/rubygems/gem_path_searcher.rb:13:in `initialize'
	from /usr/local/lib/ruby/site_ruby/1.9.1/rubygems.rb:841:in `new'
	from /usr/local/lib/ruby/site_ruby/1.9.1/rubygems.rb:841:in `block in searcher'
	from <internal:prelude>:10:in `synchronize'
	from /usr/local/lib/ruby/site_ruby/1.9.1/rubygems.rb:840:in `searcher'
	from /usr/local/lib/ruby/site_ruby/1.9.1/rubygems.rb:479:in `find_files'
	from /usr/local/lib/ruby/site_ruby/1.9.1/rubygems.rb:983:in `load_plugins'
	from /usr/local/lib/ruby/site_ruby/1.9.1/rubygems.rb:1139:in `<top (required)>'
	from <internal:lib/rubygems/custom_require>:29:in `require'
	from <internal:lib/rubygems/custom_require>:29:in `require'
	from /usr/local/bin/gem:8:in `<main>'