Erin Call

Erin Call

You Can't Spell Engineering Without Erin

And The Asset Pipeline Is So Enticing!

UPDATE: I fixed it! I had a directory assets/ with some non-site-related assets in it--layered image files, etc.--and had therefore put "assets" in my .slugignore. Apparently, Heroku was applying this to app/assets/ as well.

I'm having a bear of a time upgrading this site[1] from rails 3.0 to 3.2. The bulk of the engine work was done upstream (thanks upstream, upstream rules) but I can't get application.css to compile on Heroku. It's working locally, but on production no matter what I do, I get exceptions on pageload:

A ActionView::Template::Error occurred in posts#index:
 application.css isn't precompiled

Initially it wouldn't compile at all; per Heroku's troubleshooting tips I added config.assets.initialize_on_precompile = false to config/application.rb . Now when I push to heroku, the output log appears to be successfully precompiling my assets:

$ git push heroku master
Counting objects: 17, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (9/9), done.
Writing objects: 100% (9/9), 1.23 KiB, done.
Total 9 (delta 7), reused 0 (delta 0)

-----> Heroku receiving push
-----> Ruby/Rails app detected
-----> Installing dependencies using Bundler version 1.1.rc.7
       Running: bundle install --without development:test --path vendor/bundle --binstubs bin/ --deployment
       Fetching gem metadata from
{{snip bundle install output}}
       Your bundle is complete! It was installed into ./vendor/bundle
       Cleaning up the bundler cache.
-----> Writing config/database.yml to read from DATABASE_URL
-----> Preparing app for Rails asset pipeline
       Running: rake assets:precompile
-----> Rails plugin injection
       Injecting rails_log_stdout
       Injecting rails3_serve_static_assets
-----> Discovering process types
       Procfile declares types      -> web
       Default types for Ruby/Rails -> console, rake, worker
-----> Compiled slug size is 20.7MB
-----> Launching... done, v30

But I still get application.css isn't precompiled.

I've tried manually precompiling my assets:

$ RAILS_ENV=production bundle exec rake assets:precompile
/Users/erincall/.rvm/rubies/ruby-1.9.2-p290/bin/ruby /Users/erincall/.rvm/gems/ruby-1.9.2-p290@opinions/bin/rake assets:precompile:all RAILS_ENV=production RAILS_GROUPS=assets

$ git add public/assets
$ git commit -m "precompiled assets"
$ git push heroku master

But it has no effect. Perplexingly, I still see Running: rake assets:precompile in the Heroku slug compilation output, even though in this case I have a public/assets/manifest.yml and the Heroku docs say I should see Detected manifest.yml, assuming assets were compiled locally.

It almost looks like Heroku is expecting/putting manifest.yml somewhere other than public/assets, but I don't have much evidence to support that. I hope it's that, though, 'cause that would be a super-easy fix.

Uh the upside of this is I'm not sure I would've looked into the asset pipeline if I hadn't run into this trouble, and it turns out it's super-awesome 'cause you can just write sass and coffeescript and the framework will compile and concatenate and minify them. <3

[1] At the time this entry was written, this blog was powered by Rails. This is no longer the case, but I've retained the entry for posterity.

Posted on 2012-03-04T04:59:00Z
Posted in rails, heroku.
comments powered by Disqus