rails bootstrap-sass assets compilation error - undefined variable alert-padding

Question

all roads point to bootstrap-sass

Referral chain:

• railscast-328 (twitter bootstrap basics) refers to
• http://www.sitepoint.com/twitter-bootstrap-less-and-sass-understanding-your-options-for-rails-3-1/ which refers to
• https://github.com/jlong/sass-bootstrap which in turn exclaims there is a new official port of bootstrap to sass at
• https://github.com/twbs/bootstrap-sass which is another one of the options in the twitter-bootstrap article

It is reported as an issue with the bootstrap-rails gem: https://github.com/anjlab/bootstrap-rails/issues/91

I believe I installed it correctly

The gems

gem 'sass-rails', '>= 3.2' # sass-rails needs to be higher than 3.2
gem 'bootstrap-sass', '~> 3.1.1'

are installed (tried outside and inside of assets group), application.css.scss contains

@import "bootstrap";

only.

but it gives me an error

When attempting bundle exec rake assets:precompile it gives this error:

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 <top (required)>'
/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 `<top (required)>'
/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 `<main>'

I checked that /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 does actually import the _variables.scss file below it in the bootsrap/ directory first (prior to _alerts.scss etc), and it does... and in _variables.scss it defines $alert_padding.

I suspect I'm missing something obvious

In the environments/production.rb file I commented everything about assets out, and tried just config.assets.initialize_on_precompile = true in accordance with the manual https://github.com/twbs/bootstrap-sass

research so far

• bootstrap-sass: Undefined variable: "$baseLineHeight"
• Proper SCSS Asset Structure in Rails
• Using twitter bootstrap with rails assets pipeline and less
• https://github.com/twbs/bootstrap-sass/issues/79#issuecomment-4428595
• trying to import bootstrap via bootstrap-sass on heroku but getting an error
• https://github.com/twbs/bootstrap-sass
• https://github.com/anjlab/bootstrap-rails/issues/91
• railscast 328, 329 and 268 looking for clues
• googling about
• modifying gem's bootstrap/bootstrap.scss to use underscore and .scss, various tinkering such as commenting out lines relating to assets in environments/production.rb, commenting in only the one in the gem's page (manual) config.assets.initialize_on_precompile = true

issue identified

I copied the gem's contents into my assets directory, which is essentially what jlong's bootstrap did.

its not looking at application.css.scss... 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

Answer 1

My specific problem turned out to be some code hiding in application.rb...

how I found it

I added puts config.assets.precompile.inspect to config/environments/production.rb and marvelled at the regex it output. Then I searched the codebase for "config.assets.precompile" and lo, in application.rb, there was:

config.assets.precompile << /(^[^_\/]|\/[^_])[^\/]*$/
...
config.assets.precompile += ["*.js", "*.css", "jquery-migrate-rails.js"]

which was causing the problem. (I'm slightly puzzled as I've triple checked those regexes and they shouldn't be picking up _alerts.scss... but lets gloss over that and focus on the fact that removing those lines fixed it)

Maybe this will help someone else...

Answer 2

Don't know why but for me it helped to put into assets.rb this line

Rails.application.config.assets.precompile += [/^[-_a-zA-Z0-9]*\..*/]

Initially I had the Sass::SyntaxError: Undefined variable: "$alert-padding". problem with this line

Rails.application.config.assets.precompile += [/.*\.css/] 

But after I changed it to the first one the problem was solved and everything worked in production.

Answer 3

I was facing same issue with Rails 4. I figured out solution to overwrite the gems. For it I copy the bootstrap gem bootstrap-sass-X.X.X.X in vendors folder Than Change in Gemfile for gem path

  gem 'bootstrap-sass', '3.3.1.0', :path => 'vendor/bootstrap-sass-X.X.X.X'
  than write these 2 line
    @import "bootstrap/variables";
    @import "bootstrap/mixins";
  at top of each of file which are inside the bootstrap folder
  (vendor/bootstrap-sass-X.X.X.X/assets/stylesheets/bootstrap)

  //like for _alerts.scss

  // Alerts
  // --------------------------------------------------
    @import "bootstrap/variables";
    @import "bootstrap/mixins";

  // Base styles
  // -------------------------

Answer 4

There is an issue with globing and precompiling assets. https://github.com/twbs/bootstrap-sass/issues/863

If you must precompile your js and css assets:

Rails.application.config.assets.precompile += [proc { |filename, path| path =~ /(app|lib|vendor)\/assets/ && ['.js', '.css'].include?(File.extname(filename)) }]

Basically this proc will look in app lib and vendor folders for your assets.

Also, used a section of the Rails Guide to come up with this code