How to add Source Maps to Omega 4.x projects

SASS 3.3 introduced support for Sourcemaps and just recently, Chris Eppstein has created an initial Release Candidate as a lead up to a full 1.0.0 release version of Compass — which now also supports Sourcemaps.

However, the Omega 4.x theme for Drupal 7 is running on older “stable” versions of Sass, Compass, and their respective dependencies — none of which support source maps.

UPDATE: fubhy (the Omega theme maintainer) has committed code to the Omega 7.x-4.x branch that adds Source Maps functionality. Just grab the latest dev release, create a sub theme from the starter kit and test! Leave your feedback on [Issue #2311593](

While source maps are not “bleeding edge” like they were about a year ago, they are relatively new technology only really being supported in the latest versions of a few browsers like Chrome and Firefox. I consider sourcemaps to be an important tool for distributed larger projects with many components and partials, particularly for teams with multiple front-end developers.

The steps below are the ones I took to get Omega updated to work with sourcemaps. I’ve provide a patch to the Omega issue #2311593.

The assumption here is that you’re already following Omega’s best practices and using bundler and RVM to manage your ruby-version, and the gem set that the Omega sub theme depends on. The way to confirm this is to just run bundle install from inside your theme folder and follow that up with a bundle show sass, which should give you a path that looks something like ~/.rvm/gems/ruby-[version]@omega.themename/gems/.

If you’re not using RVM, that’s o.k., but I highly recommend you start using it to control which ruby version you’re using in any given project.

1. Update to SASS 3.3 and Compass 1.0.0.rc.0

Go to your theme folder and change the sass gem to ~>3.3 and compass gem to ~>1.0.0.rc.0 in the Gemfile file. The spermy operator ~> effectively means the last digit on the right may be equal to or greater than the value specified and is sometimes pronounced as “approximately greater than”.

In your theme’s Gemfile, replace: gem 'sass' with: gem 'sass', '~>3.3', and then replace gem 'compass' with: gem 'compass', ‘~>1.0.0.rc.0'.

2. Use bundler to update the SASS and Compass gems.

bundle update

This has the effect of downloading new Ruby gems and updating the Gemfile.lock file. New versions of the SASS and Compass gems will be installed into the theme’s gemset — typically found inside ~/.rvm/gems/ruby-[version]@omega.themename/gems/ folder (if you’re using RVM).

3 Remove add_import_path from config.rb.

The line add_import_path 'sass' in the config.rb file was causing problems after upgrading compass because it was generating css files twice – so I had to remove this line.

(via and

4. Compile your CSS.

bundle exec compass compile

You’ll probably run into a handful of errors trying to compile the CSS due to other outdated and deprecated functions. In my case I got a series of compile errors that I was able to remedy one-by-one, by searching for the error message in Google and following the instructions to remedy accordingly.

Error 1:

WARNING: The compass/css3/shared module has been deprecated.

You can silence this warning by importing compass/css3/deprecated-support instead.

on line 1 of compass-core-1.0.0.rc.0/stylesheets/compass/css3/_shared.scss
from line 1 of singularitygs-1.1.2/stylesheets/singularitygs/helpers/_box-sizing.scss
from line 8 of singularitygs-1.1.2/stylesheets/singularitygs/_helpers.scss
from line 36 of singularitygs-1.1.2/stylesheets/_singularitygs.scss
from line 4 of sites/all/themes/themename/sass/themename.styles.scss
from line 5 of sites/all/themes/themename/sass/

This happens because version 1.0.0 that comes with Omega is incompatible with Sass 3.3.

5. Update to 1.2.1

In the Gemfile, update singulartygs gem to ~>1.2.1 and also add require 'singularitygs'to the config.rb file. Then run bundle update, and bundle exec compass compile. This results in another error.

Error 2:

Line 3 of sass/themename.styles.scss: File to import not found or unreadable: breakpoint.

6. Update to breakpoint 2.4.0

In the Gemfile, update breakpoint gem to ~>2.4.0 and also add require 'breakpoint' to config.rb (more info).

7. Update to Sass Globbing 1.1.0

In the Gemfile, update Sass Globbing gem to ~>1.1.0 in Gemfile. Re-run bundle update and bundle exec compass compile (more info).

This results in yet another error:

Error 3:

Line 8 of sass/themename.normalize.scss: File to import not found or unreadable: toolkit/border-box.

8. Update to Toolkit 2.5.2 and fix import statements in SCSS files

This requires three changes (more info):

  1. In Gemfile update the toolkit gem to ~> 2.5.2.
  2. In sass/themename.styles.scss change from @import "toolkit-no-css" to @import "toolkit".
  3. In sass/themename.normalize.scss change from @import "toolkit/border-box" to @import "toolkit/kickstart".

9. Update to Susy 2.1.2

Update the susy gem to ~>2.1.2 in the Gemfile.

I just did this because there was another error related to susy, and wanted to be sure we were on the latest version. Unfortunately, I don’t remember the error message now.

10. Run and re-run bundle exec compass compile until there are no more errors.

Following the methodology in the previous steps above to troubleshoot and upgrade libraries as necessary, as you hit errors.

11. Enable Compass Sourcemap configuration in config.rb.

Once there are no more errors, you can finally enable the source map configuration. On the line for sass_options in config.rb, add :sourcemap => true inside the curly braces.

My setup looks like this:

sass_options = {
  :debug_info => false,
  :line_comments => false,
  :sourcemap => true

I have output_style = :expanded and debug_info hardcoded to false for two reasons:

We don’t use the :development or :production configurations provided by ruby and available to Compass to distinguish between how compressed the css output is. Drupal has built in functionality to aggregate and minify all the CSS, which we turn on only on testing and production environments.

We commit the compiled CSS to our repository, because we don’t run compass or bundler on our production servers. Thus it is far better to store compiled css in an expanded format so that diffs and commit history from other front-end developers can easily be read by a human.

12. Generate source maps!

Run bundle exec compass compile once more to compile the css again and generate the source maps.

You will end up with new files in your theme’s css/ directory that look like css/ etc.

13. Commit the changes.

Commit all the changes in your theme, including in the Gemfile, the Gemfile.lock, the config.rb, the changes to your SASS files, and the newly generated your new CSS map files into your version control repository.

git commit .  -m "Added sourcemaps!”
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