Question

I first switch to a separate heroku_branch branch to keep the precompiled assets from “poluting” my git repository then merge with the master repository

$ git checkout heroku_branch
$ git merge master

I’ve done exactly what heroku’s documentation recommends with resepect to precompiling assets

$ RAILS_ENV=production bundle exec rake assets:precompile

/Users/bagvoo/.rvm/rubies/ruby-1.9.2-p290/bin/ruby /Users/bagvoo/.rvm/gems/ruby-1.9.2-p290@upvote/bin/rake assets:precompile:all RAILS_ENV=production RAILS_GROUPS=assets
/Users/bagvoo/.rvm/rubies/ruby-1.9.2-p290/bin/ruby /Users/bagvoo/.rvm/gems/ruby-1.9.2-p290@upvote/bin/rake assets:precompile:nondigest RAILS_ENV=production RAILS_GROUPS=assets

$ git add .
$ git commit -m "vendor compiled assets"

Then I push to the heroku repository using

$ git push heroku master

However, I don’t get

-----> Preparing Rails asset pipeline
       Detected manifest.yml, assuming assets were compiled locally

Instead I get:

----> Preparing app for Rails asset pipeline
      Running: rake assets:precompile
      rake aborted!
      undefined method `blamed_files' for nil:NilClass
      (in /tmp/build_6x7f3k642z8z/vendor/bundle/ruby/1.9.1/gems/actionpack-3.1.1/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb)

      Tasks: TOP => assets:precompile:primary
      (See full trace by running task with --trace)
      Precompiling assets failed, enabling runtime asset compilation

There is a public/assets/manifest.yml so I don’t understand why heroku is trying to precompile these things…

Answer 1

The problem is that I was pushing from the wrong branch.

Was

$ git push heroku master

Is

$ git push heroku heroku_branch:master

This is specific to the case above where you have a separate branch from the master branch that you are pushing from.