title: Fog provider can't be blank - fog-aws-asset_sync
body: <p>Ugh, I'm getting the same error as here....<a href="https://stackoverflow.com/questions/13750690/rails-assetsprecompile-during-slug-for-s3-error-fog-provider-and-directory-can">rails assets:precompile during slug for s3 error: Fog provider and directory can&#39;t be blank when env are set</a> on the solution is not working...</p>
  
  <p>When I try to precompile assets, I get the following error:</p>
  
  <pre><code>$ RAILS_ENV=production bundle exec rake assets:precompile
  /Users/me/.rvm/rubies/ruby-1.9.3-p362/bin/ruby /Users/me/.rvm/gems/ruby-1.9.3-p362@global/bin/rake assets:precompile:all RAILS_ENV=production RAILS_GROUPS=assets
  AssetSync: using default configuration from built-in initializer
  AssetSync: using default configuration from built-in initializer
  rake aborted!
  Fog provider can't be blank
  /Users/me/.rvm/gems/ruby-1.9.3-p362/gems/asset_sync-0.5.4/lib/asset_sync/asset_sync.rb:32:in `sync'
  /Users/me/.rvm/gems/ruby-1.9.3-p362/gems/asset_sync-0.5.4/lib/tasks/asset_sync.rake:3:in `block in
  </code></pre>
  
  <p>When I type heroku labs:list ... it shows that user-env-compile is enabled</p>
  
  <pre><code>[+] user-env-compile       Add user config vars to the environment during slug compilation
  </code></pre>
  
  <p>When I type heroku config...I can see that the fog variables are setup</p>
  
  <pre><code>AWS_ACCESS_KEY_ID:            myid
  AWS_SECRET_ACCESS_KEY:        mykey
  FOG_DIRECTORY:                mydirectory
  FOG_PROVIDER:                 AWS
  </code></pre>
  
  <p>Why does it precompile some of the files, but then give the error?</p>