Latest autoprefixer (0.6.20130721) fails with an exception

[Leonya]

Running "autoprefixer:dist" (autoprefixer) task
Warning: Cannot call method 'slice' of undefined Use --force to continue.
TypeError: Cannot call method 'slice' of undefined
    at utils.clone.keyframes (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer/keyframes.js:18:30)
    at Array.map (native)
    at Keyframes.clone (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer/keyframes.js:16:40)
    at Keyframes.cloneWithPrefix (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer/keyframes.js:29:20)
    at /Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer/processor.js:16:28
    at Prefixes.each (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer/prefixes.js:135:25)
    at /Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer/processor.js:15:31
    at CSS.eachKeyframes (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer/css.js:21:11)
    at Processor.add (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer/processor.js:11:11)
    at Autoprefixer.rework (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer.js:59:31)
    at Autoprefixer.rework (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer.js:4:61)
    at Autoprefixer.compile (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/node_modules/autoprefixer/lib/autoprefixer.js:52:12)
    at /Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/tasks/autoprefixer.js:42:47
    at Array.forEach (native)
    at Object.<anonymous> (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt-autoprefixer/tasks/autoprefixer.js:21:20)
    at Object.<anonymous> (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt/lib/grunt/task.js:258:15)
    at Object.thisTask.fn (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt/lib/grunt/task.js:78:16)
    at Object.<anonymous> (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt/lib/util/task.js:282:30)
    at Task.runTaskFn (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt/lib/util/task.js:235:24)
    at Task.<anonymous> (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt/lib/util/task.js:281:12)
    at Task.<anonymous> (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt/lib/util/task.js:215:7)
    at Task.runTaskFn (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt/lib/util/task.js:238:9)
    at Task.<anonymous> (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt/lib/util/task.js:281:12)
    at Task.<anonymous> (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt/lib/util/task.js:215:7)
    at null._onTimeout (/Users/leonidkhachaturov/code/hdt/webui/playground/node_modules/grunt/lib/util/task.js:225:33)
    at Timer.listOnTimeout [as ontimeout] (timers.js:110:15)

[Leonya]

I can provide the CSS, if you need it for debugging.

[okonet]

This issue is a combination of https://github.com/gruntjs/grunt-contrib-compass in development environment. Compass (SCSS) includes line comments into the generated CSS file:

/* line 42, ../../app/styles/main.scss */
html,
body,
.app {
  height: 100%;
  width: 100%;
  overflow: hidden;
}

This option is enabled by default for grunt-contrib-compass. Autoprefixer doesn't fail when using following config for compass task in your Gruntfile:

compass:
    server:
        options:
          environment: 'development'
          noLineComments: yes

[ai]

@okonet and this comments broke Autoprefixer? I can fix parser if you give me good example

[ai]

@okonet this comments doesn’t broke Autoprefixer:

~/Dev/autoprefixer → echo "/* line 42, ../../app/styles/main.scss */
.app {
  overflow: hidden;
}" | ./bin/autoprefixer 
/* line 42, ../../app/styles/main.scss */

.app {
  overflow: hidden;
}

@Leonya wait your CSS to debug. If it possiblt, please try to find (like binary search) smallest part of CSS, that broke Autoprefixer :).

[ai]

Issue was in comments in keyframes, @demiazz find it and fix: c9a1477

Tomorrow will be new release with fix.