Carrierwave 500s with "TypeError (no implicit conversion of nil into String)" when not on Heroku

[rick]

I have a patch for this over in https://github.com/rick/balder/pull/1, specifically https://github.com/rick/balder/commit/81af9e7eedef9cf5a1d676213f888d6cfee40fa7 but I'm not clear on what the various concerns are (and whether this will break something for other folks).

I was seeing these sort of errors consistently:

TypeError (no implicit conversion of nil into String):
  app/controllers/photos_controller.rb:80:in `create'
  app/middleware/flash_session_cookie_middleware.rb:16:in `call'

The cache_dir method, which carrierwave seems to rely on, is only defined on Heroku + S3 configurations. It might actually need to be widened to be defined on all configurations, but I'm at least relying on S3 myself, so not sure.

[espen]

What server are you using? I would assume that the tmp directory would be writable otherwise (Heroku is sortof read-only).

[rick]

I'm on a digitalocean VPS for this installation, nginx + unicorn. The problem doesn't appear to be one of whether the temp directory is writeable, but rather one of the call to cache_dir from inside carrierwave blows up because there's no implementation of cache_dir in scope when using S3 but not using Heroku.

Would it be more appropriate to delegate to some other default in the non-Heroku case? I looked back at the history of the file and couldn't infer what the intent was when I tracked down the problem.

[coneybeare]

I am seeing this problem problem when uploading on a private server as well as localhost.

Completed 500 Internal Server Error in 952ms

TypeError (can't convert nil into String):
  app/controllers/photos_controller.rb:82:in `create'
  app/middleware/flash_session_cookie_middleware.rb:16:in `call'

[espen]

And it works when setting the tmp dir? I'm a bit confused with the error message if the problem is not being able to store to disk.

[coneybeare]

I am not sure that that is the problem, the error message is pretty vague. I am using s3 and not heroku, so maybe the cache_dir thing is the problem, maybe not. Is there anything you want me to experiment with to help debug?

[espen]

A full stack trace would help. Try changing this and see if that helps. https://github.com/rick/balder/commit/81af9e7eedef9cf5a1d676213f888d6cfee40fa7

[coneybeare]

Not necessary. I just commented out the cache_dir method and it worked. So the problem is that you are returning false from the cache_dir method in file_uploader.rb when not using heroku instead of calling super or the default it expects (I think).

[coneybeare]

Hm, spoke too soon. Worked locally, but not on the remote server.

[coneybeare]

Sorry for the smap, twas a caching issue. This fix works for me both locally and on my remote non-heroku server with s3