message: drake: sort the environment when showing it
diff: @@ -3935,7 +3935,7 @@ class Runner(Builder):
  print(header, file = err, flush = True)
  if self.__env is not None:
  output_env = ('%s=%s ' % (var, pipes.quote(str(value)))
  - for var, value in self.__env.items())
  + for var, value in sorted(self.__env.items()))
  else:
  output_env = ()
  output_cmd = (pipes.quote(str(a)) for a in self.command)
  