When I set debug to false, firebug @media is not deleted

[storuky]

When I set debug to false, firebug comments is not deleted. I write in initializers/stylus.rb:

require 'stylus'
Stylus.debug = false

in environments/development.rb

config.assets.debug = false

But I see in my css files @media query... These settings do not affect anything or I do something wrong? I just want to write @Keyframes animation.

@keyframes flipInX
  0%
    transform: perspective(400px) rotateX(90deg)
    opacity: 0

  40%
    transform: perspective(400px) rotateX(-10deg)

  70%
    transform: perspective(400px) rotateX(10deg)

  100%
    transform: perspective(400px) rotateX(0deg)
    opacity: 1

But this extra comment and media query generate invalide code:

@media -stylus-debug-info{filename{font-family:file\:\/\/\/Users\/pavelkononenko\/devel\/wheat\/app\/assets\/stylesheets\/components\/dropdown\.styl}line{font-family:\0000321}}
@keyframes flipInX {

/* line 22 : /Users/pavelkononenko/devel/wheat/app/assets/stylesheets/components/dropdown.styl */

@media -stylus-debug-info{filename{font-family:file\:\/\/\/Users\/pavelkononenko\/devel\/wheat\/app\/assets\/stylesheets\/components\/dropdown\.styl}line{font-family:\0000322}}
  0% {
    transform: perspective(400px) rotateX(90deg);
    opacity: 0;
  }

/* line 26 : /Users/pavelkononenko/devel/wheat/app/assets/stylesheets/components/dropdown.styl */

@media -stylus-debug-info{filename{font-family:file\:\/\/\/Users\/pavelkononenko\/devel\/wheat\/app\/assets\/stylesheets\/components\/dropdown\.styl}line{font-family:\0000326}}
  40% {
    transform: perspective(400px) rotateX(-10deg);
  }

/* line 29 : /Users/pavelkononenko/devel/wheat/app/assets/stylesheets/components/dropdown.styl */

@media -stylus-debug-info{filename{font-family:file\:\/\/\/Users\/pavelkononenko\/devel\/wheat\/app\/assets\/stylesheets\/components\/dropdown\.styl}line{font-family:\0000329}}
  70% {
    transform: perspective(400px) rotateX(10deg);
  }

/* line 32 : /Users/pavelkononenko/devel/wheat/app/assets/stylesheets/components/dropdown.styl */

@media -stylus-debug-info{filename{font-family:file\:\/\/\/Users\/pavelkononenko\/devel\/wheat\/app\/assets\/stylesheets\/components\/dropdown\.styl}line{font-family:\0000332}}
  100% {
    transform: perspective(400px) rotateX(0deg);
    opacity: 1;
  }
}