def determine_path
      if source_line.file == SourceLine::DEFAULT_FILE
        return source_line.file
      end

      full_path = File.expand_path(source_line.file)
      pwd       = Dir.pwd

      if full_path.start_with?(pwd)
        from = Pathname.new(full_path)
        to   = Pathname.new(pwd)

        return from.relative_path_from(to).to_s
      else
        return full_path
      end
    end
def determine_path
      if source_line.file == SourceLine::DEFAULT_FILE
        return source_line.file
      end

      full_path = File.expand_path(source_line.file)
      pwd       = Dir.pwd

      if full_path.start_with?(pwd)
        from = Pathname.new(full_path)
        to   = Pathname.new(pwd)

        return from.relative_path_from(to).to_s
      else
        return full_path
      end
    end
Returns the path to the source of the message. If the path resides in the
 current working directory (or a child directory) the path is relative,
 otherwise it's absolute.

 @return [String]