When pushing to Heroku, we're seeing the following line in the output:
...
Error detecting the assets:precompile task
...
The app will then successfully deploy, but it won't have any assets.
This is incredibly frustrating, because no error is raised, and we don't have a clue what might be going on. The logs don't hint to anything.
Here's the tail of the terminal output for the push:
Your bundle is complete! It was installed into ./vendor/bundle
Cleaning up the bundler cache.
-----> Writing config/database.yml to read from DATABASE_URL
Error detecting the assets:precompile task
-----> Discovering process types
Procfile declares types -> (none)
Default types for Ruby/Rails -> console, rake, web, worker
-----> Compiled slug size: 54.8MB
-----> Launching... done, v15
http://myapp-1234.herokuapp.com deployed to Heroku
Here's the complete papertrail log output throughout the push:
Sep 29 09:07:32 myapp-1234 heroku/slug-compiler: Slug compilation started
Sep 29 09:07:54 myapp-1234 heroku/api: Release v15 created by me@example.com
Sep 29 09:07:56 myapp-1234 heroku/slug-compiler: Slug compilation finished
Sep 29 09:08:00 myapp-1234 heroku/web.1: Process exited with status 143
Sep 29 09:08:00 myapp-1234 heroku/web.1: Starting process with command `bin/rails server -p 18025 -e staging`
Sep 29 09:08:04 myapp-1234 app/web.1: [2013-09-29 16:08:04] INFO WEBrick 1.3.1
Sep 29 09:08:05 myapp-1234 app/web.1: [2013-09-29 16:08:04] INFO ruby 2.0.0 (2013-06-27) [x86_64-linux]
Sep 29 09:08:05 myapp-1234 app/web.1: [2013-09-29 16:08:04] INFO WEBrick::HTTPServer#start: pid=2 port=18025
Sep 29 09:08:05 myapp-1234 heroku/web.1: State changed from starting to up
Great- we learned nothing.
What can we do to debug errors during Heroku compilation?