message: drake: when DRAKE_PRETTY, make env more readable
diff: @@ -47,6 +47,7 @@ def path_source(path = None):
  else:
  return Drake.current.path_source / Drake.current.prefix / path
  +PRETTY = 'DRAKE_PRETTY' in os.environ
  PROFILE = 'DRAKE_PROFILE' in os.environ
  class Drake:
  @@ -1747,13 +1748,16 @@ def command(cmd, cwd = None, stdout = None, env = None):
  def command_flatten(command, env = None):
  - if env is not None:
  - output_env = ('%s=%s' % (var, pipes.quote(str(value)))
  - for var, value in env.items())
  + if env:
  + env = ('%s=%s' % (var, pipes.quote(str(env(value))))
  + for var in sorted(env.keys()))
  + if PRETTY:
  + env = ' \\\n '.join(env) + ' \\\n'
  else:
  - output_env = ()
  - return ' '.join(chain(output_env,
  - (pipes.quote(str(a)) for a in command)))
  + env = ' '.join(chain(env)) + ' '
  + else:
  + env = ''
  + return env + ' '.join(pipes.quote(str(a)) for a in command)
  class Builder:
  