# File lib/bundler/rubygems_ext.rb, line 45
    def full_gem_path
      # this cannot check source.is_a?(Bundler::Plugin::API::Source)
      # because that _could_ trip the autoload, and if there are unresolved
      # gems at that time, this method could be called inside another require,
      # thus raising with that constant being undefined. Better to check a method
      if source.respond_to?(:path) || (source.respond_to?(:bundler_plugin_api_source?) && source.bundler_plugin_api_source?)
        Pathname.new(loaded_from).dirname.expand_path(source.root).to_s.untaint
      else
        rg_full_gem_path
      end
    end