title: rails bootstrap-sass assets compilation error - undefined variable alert-padding
body: <h2>all roads point to bootstrap-sass</h2>
  
  <p>Referral chain:</p>
  
  <ul>
  <li>railscast-328 (twitter bootstrap basics) refers to </li>
  <li><a href="http://www.sitepoint.com/twitter-bootstrap-less-and-sass-understanding-your-options-for-rails-3-1/" rel="noreferrer">http://www.sitepoint.com/twitter-bootstrap-less-and-sass-understanding-your-options-for-rails-3-1/</a> which refers to </li>
  <li><a href="https://github.com/jlong/sass-bootstrap" rel="noreferrer">https://github.com/jlong/sass-bootstrap</a> which in turn exclaims there is a new official port of bootstrap to sass at </li>
  <li><a href="https://github.com/twbs/bootstrap-sass" rel="noreferrer">https://github.com/twbs/bootstrap-sass</a> which is another one of the options in the twitter-bootstrap article</li>
  </ul>
  
  <p>It is reported as an issue with the bootstrap-rails gem: <a href="https://github.com/anjlab/bootstrap-rails/issues/91" rel="noreferrer">https://github.com/anjlab/bootstrap-rails/issues/91</a></p>
  
  <h2>I believe I installed it correctly</h2>
  
  <p>The gems</p>
  
  <pre><code>gem 'sass-rails', '&gt;= 3.2' # sass-rails needs to be higher than 3.2
  gem 'bootstrap-sass', '~&gt; 3.1.1'
  </code></pre>
  
  <p>are installed (tried outside and inside of assets group), application.css.scss contains</p>
  
  <pre><code>@import "bootstrap";
  </code></pre>
  
  <p>only.</p>
  
  <h2>but it gives me an error</h2>
  
  <p>When attempting <code>bundle exec rake assets:precompile</code> it gives this error:</p>
  
  <pre><code>rake aborted!
  Undefined variable: "$alert-padding".
    (in /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/bootstrap-sass-3.1.1.0/vendor/assets/stylesheets/bootstrap/_alerts.scss)
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/bootstrap-sass-3.1.1.0/vendor/assets/stylesheets/bootstrap/_alerts.scss:10
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/script/variable.rb:49:in `_perform'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/script/node.rb:40:in `perform'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:298:in `visit_prop'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:37:in `visit'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:100:in `visit'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:53:in `block in visit_children'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:53:in `map'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:53:in `visit_children'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:109:in `block in visit_children'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:121:in `with_environment'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:108:in `visit_children'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:37:in `block in visit'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:320:in `visit_rule'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:37:in `visit'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:100:in `visit'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:53:in `block in visit_children'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:53:in `map'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:53:in `visit_children'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:109:in `block in visit_children'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:121:in `with_environment'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:108:in `visit_children'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:37:in `block in visit'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:128:in `visit_root'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/base.rb:37:in `visit'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:100:in `visit'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/visitors/perform.rb:7:in `visit'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/tree/root_node.rb:20:in `render'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/engine.rb:315:in `_render'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-3.2.7/lib/sass/engine.rb:262:in `render'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sass-rails-3.2.6/lib/sass/rails/template_handlers.rb:106:in `evaluate'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/tilt-1.3.7/lib/tilt/template.rb:77:in `render'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/context.rb:193:in `block in evaluate'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/context.rb:190:in `each'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/context.rb:190:in `evaluate'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/processed_asset.rb:16:in `initialize'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/base.rb:18:in `new'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/base.rb:18:in `block in build_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:270:in `circular_call_protection'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/base.rb:14:in `build_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/index.rb:93:in `block in build_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/caching.rb:19:in `cache_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/index.rb:92:in `build_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:169:in `find_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/index.rb:14:in `find_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/bundled_asset.rb:12:in `initialize'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/base.rb:22:in `new'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/base.rb:22:in `build_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/index.rb:93:in `block in build_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/caching.rb:19:in `cache_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/index.rb:92:in `build_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:169:in `find_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/index.rb:14:in `find_asset'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/static_compiler.rb:41:in `block in compile'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:219:in `block in each_logical_path'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:206:in `block (2 levels) in each_file'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:196:in `each'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:196:in `each_entry'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:204:in `block in each_file'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:203:in `each'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:203:in `each_file'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sprockets-2.2.2/lib/sprockets/base.rb:217:in `each_logical_path'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/sprockets_overrides/static_compiler.rb:29:in `compile'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/tasks/assets.rake:108:in `internal_precompile'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/turbo-sprockets-rails3-0.3.11/lib/turbo-sprockets/tasks/assets.rake:115:in `block (3 levels) in &lt;top (required)&gt;'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:246:in `call'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:246:in `block in execute'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:241:in `each'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:241:in `execute'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:184:in `block in invoke_with_call_chain'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:177:in `invoke_with_call_chain'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:170:in `invoke'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:143:in `invoke_task'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:101:in `block (2 levels) in top_level'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:101:in `each'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:101:in `block in top_level'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:110:in `run_with_threads'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:95:in `top_level'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:73:in `block in run'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:160:in `standard_exception_handling'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:70:in `run'
  /home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/rake-10.0.4/bin/rake:33:in `&lt;top (required)&gt;'
  /home/joe/.rbenv/versions/1.9.3-p448/bin/rake:23:in `load'
  /home/joe/.rbenv/versions/1.9.3-p448/bin/rake:23:in `&lt;main&gt;'
  </code></pre>
  
  <p>I checked that <code>/home/joe/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/bootstrap-sass-3.1.1.0/vendor/assets/stylesheets/bootstrap.scss</code> does actually import the _variables.scss file below it in the <code>bootsrap/</code> directory first (prior to _alerts.scss etc), and it does... and in _variables.scss it defines $alert_padding.</p>
  
  <h2>I suspect I'm missing something obvious</h2>
  
  <p>In the <code>environments/production.rb</code> file I commented everything about assets out, and tried just <code>config.assets.initialize_on_precompile = true</code> in accordance with the manual <code>https://github.com/twbs/bootstrap-sass</code></p>
  
  <h2>research so far</h2>
  
  <ul>
  <li><a href="https://stackoverflow.com/questions/9915950/bootstrap-sass-undefined-variable-baselineheight">bootstrap-sass: Undefined variable: &quot;$baseLineHeight&quot;</a></li>
  <li><a href="https://stackoverflow.com/questions/9138946/proper-scss-asset-structure-in-rails">Proper SCSS Asset Structure in Rails</a></li>
  <li><a href="https://stackoverflow.com/questions/10281907/using-twitter-bootstrap-with-rails-assets-pipeline-and-less">Using twitter bootstrap with rails assets pipeline and less</a></li>
  <li><a href="https://github.com/twbs/bootstrap-sass/issues/79#issuecomment-4428595" rel="noreferrer">https://github.com/twbs/bootstrap-sass/issues/79#issuecomment-4428595</a></li>
  <li><a href="https://stackoverflow.com/questions/15445480/trying-to-import-bootstrap-via-bootstrap-sass-on-heroku-but-getting-an-error?rq=1">trying to import bootstrap via bootstrap-sass on heroku but getting an error</a></li>
  <li><a href="https://github.com/twbs/bootstrap-sass" rel="noreferrer">https://github.com/twbs/bootstrap-sass</a></li>
  <li><a href="https://github.com/anjlab/bootstrap-rails/issues/91" rel="noreferrer">https://github.com/anjlab/bootstrap-rails/issues/91</a></li>
  <li>railscast 328, 329 and 268 looking for clues</li>
  <li>googling about</li>
  <li>modifying gem's bootstrap/bootstrap.scss to use underscore and .scss, various tinkering such as commenting out lines relating to assets in <code>environments/production.rb</code>, commenting in only the one in the gem's page (manual) <code>config.assets.initialize_on_precompile = true</code></li>
  </ul>
  
  <h2>issue identified</h2>
  
  <p>I copied the gem's contents into my assets directory, which is essentially what jlong's bootstrap did.</p>
  
  <p>its not looking at <code>application.css.scss</code>... its ignoring what I put in there and electing to instead look into the folders and loading those files. Which is why it sees alerts.scss first. I tried changing the name of _variables.scss to _aavariables.scss to no avail</p>