こんなエラー
DEPRECATION WARNING: You have Rails 2.3-style plugins in vendor/plugins! Support for these plugins will be removed in Rails 4.0. Move them out and bundle them in your Gemfile, or fold them in to your app as lib/myplugin/* and config/initializers/myplugin.rb. See the release notes for more on this: http://weblog.rubyonrails.org/2012/01/04/rails-3-2-0-rc2-has-been-released. (called from <top (required)> at /tmp/build_aq7o5mp0iokp/Rakefile:7)
下のほうに以下のシテキ
-----> Rails plugin injection
Injecting rails_log_stdout
Injecting rails3_serve_static_assets
解決策はここ.
http://help.papertrailapp.com/discussions/questions/116-logging-from-heroku-apps-using-unicorn
Solution
To output app logs, edit config/environments/production.rb
or the environment configuration for your Heroku environment.
In the MyApp::Cofiguration.configure .. end
block, add these 2 lines:
config.logger = Logger.new(STDOUT)
config.logger.level = Logger.const_get(ENV['LOG_LEVEL'] ? ENV['LOG_LEVEL'].upcase : 'INFO')
だそうです.