# File lib/sass/environment.rb, line 103
    def stack_trace
      trace = []
      stack.reverse.each_with_index do |entry, i|
        msg = "#{i == 0 ? "on" : "from"} line #{entry[:line]}"
        msg << " of #{entry[:filename] || "an unknown file"}"
        msg << ", in `#{entry[:mixin]}'" if entry[:mixin]
        trace << msg
      end
      trace
    end