    # File lib/chef/provider/package/rubygems.rb, line 101
              def candidate_version_from_file(gem_dependency, source)
                spec = Gem::Format.from_file_by_path(source).spec
                if spec.satisfies_requirement?(gem_dependency)
                  logger.debug {"#{@new_resource} found candidate gem version #{spec.version} from local gem package #{source}"}
                  spec.version
                else
                  # This is probably going to end badly...
                  logger.warn { "#{@new_resource} gem package #{source} does not satisfy the requirements #{gem_dependency.to_s}" }
                  nil
                end
              end