title: Django collectstatic not working with django-pipeline and yui-compressor
body: <p>I've installed <a href="https://github.com/cyberdelia/django-pipeline/" rel="nofollow">django-pipeline</a> on my Django 1.4.1 application under a virtualenv but when I run <code>python manage.py collectstatic</code>, I get:</p>
  
  <pre><code>Traceback (most recent call last):
    File "./manage.py", line 11, in &lt;module&gt;
      execute_manager(settings)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/django/core/management/__init__.py", line 459, in execute_manager
      utility.execute()
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/django/core/management/__init__.py", line 382, in execute
      self.fetch_command(subcommand).run_from_argv(self.argv)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/django/core/management/base.py", line 196, in run_from_argv
      self.execute(*args, **options.__dict__)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/django/core/management/base.py", line 232, in execute
      output = self.handle(*args, **options)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/django/core/management/base.py", line 371, in handle
      return self.handle_noargs(**options)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/django/contrib/staticfiles/management/commands/collectstatic.py", line 163, in handle_noargs
      collected = self.collect()
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/django/contrib/staticfiles/management/commands/collectstatic.py", line 119, in collect
      dry_run=self.dry_run)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/pipeline/storage.py", line 30, in post_process
      packager.pack_stylesheets(package)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/pipeline/packager.py", line 90, in pack_stylesheets
      variant=package.variant, **kwargs)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/pipeline/packager.py", line 100, in pack
      content = compress(paths, **kwargs)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/pipeline/compressors/__init__.py", line 76, in compress_css
      css = getattr(compressor(verbose=self.verbose), 'compress_css')(css)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/pipeline/compressors/yui.py", line 14, in compress_css
      return self.compress_common(css, 'css', settings.PIPELINE_YUI_CSS_ARGUMENTS)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/pipeline/compressors/yui.py", line 8, in compress_common
      return self.execute_command(command, content)
    File "/home/hg/VIRTUALENVS/movie/lib/python2.6/site-packages/pipeline/compressors/__init__.py", line 235, in execute_command
      pipe.stdin.write(smart_str(content))
  IOError: [Errno 32] Broken pipe
  </code></pre>
  
  <p>My settings are:</p>
  
  <pre><code># static
  STATIC_ROOT = join(REPOSITORY_ROOT, 'static_collected')
  STATIC_URL = '/static/'
  STATICFILES_DIRS = (join(REPOSITORY_ROOT, 'static'),)
  STATICFILES_FINDERS = (
      'django.contrib.staticfiles.finders.FileSystemFinder',
      'django.contrib.staticfiles.finders.AppDirectoriesFinder',
  )
  
  # pipeline (css/js compression)
  STATICFILES_STORAGE = 'pipeline.storage.PipelineCachedStorage'
  PIPELINE = True
  PIPELINE_CSS = {
      'base_style': {
          'source_filenames': (
              'css/style.css',
              'css/effects.css',
              'css/rs_style.css',
              'css/jq/jquery-ui-movieplayer.css',
          ),
          'output_filename': 'CACHE/css/style.css',
      },
  }
  
  PIPELINE_JS = {
      'base_scripts': {
          'source_filenames': (
            'js/jq/jquery.js',
            'js/mv.core.js',
            'js/toolbox/toolbox.core.js',
            'js/swfobject.js',
            'swf/jwplayer5.9.2156.js',
            'js/jq/jquery-ui.custom.min.js',
            'js/mongo_autocomplete.js',
            'js/rs_script.js',
          ),
          'output_filename': 'CACHE/js/scripts.js',
      }
  }
  </code></pre>
  
  <p>Before adding django-pipeline the management command worked well, it found everything, so it's not an issue related to finding the static files nor to directory permissions.
  The Yuicompressor is installed globally and can be found under <code>/usr/local/bin/yuicompressor</code> so I didn't modify <code>PIPELINE_YUI_BINARY</code> in my settings.</p>
  
  <p>Any clue?
  Thank you!</p>