ActiveRecord :: AdapterNotSpecified - データベースが設定されていません

Question

私のRuby on RailsアプリケーションをBluemixにプッシュするときに、このエラーが発生しました。私のアプリは、実際にデータベースを必要としませんが、私は

database.yml: 
default: &default 
    adapter: sqlite3 
    pool: 5 
    timeout: 5000 

development: 
    <<: *default 
    database: db/development.sqlite3 

test: 
    <<: *default 
    database: db/test.sqlite3 

production: 
    <<: *default 
    database: db/production.sqlite3 

にそして、私のGemfileに次のようにあります

 Could not detect rake tasks 
     ensure you can run `$ bundle exec rake -P` against your app with no environment variables present 
     and using the production group of your Gemfile. 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.1/lib/active_support/values/time_zone.rb:285: warning: circular argument reference - now 
     DEPRECATION WARNING: Passing a string to ActiveRecord::Base.establish_connection for a configuration lookup is deprecated, please pass a symbol (:"") instead. (called from <top (required)> at /tmp/staged/app/Rakefile:6) 
     rake aborted! 
     ActiveRecord::AdapterNotSpecified: '' database is not configured. Available: ["production"] 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/connection_specification.rb:257:in `resolve_symbol_connection' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/connection_specification.rb:240:in `resolve_string_connection' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/connection_specification.rb:267:in `resolve_hash_connection' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/connection_specification.rb:228:in `resolve_connection' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/connection_specification.rb:152:in `resolve' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/connection_specification.rb:164:in `block in resolve_all' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/connection_specification.rb:163:in `each' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/connection_specification.rb:163:in `resolve_all' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/connection_handling.rb:69:in `resolve' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/core.rb:46:in `configurations=' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/core.rb:48:in `block in <module:Core>' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.1/lib/active_support/concern.rb:120:in `class_eval' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.1/lib/active_support/concern.rb:120:in `append_features' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/base.rb:297:in `include' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/base.rb:297:in `<class:Base>' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/base.rb:282:in `<module:ActiveRecord>' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/base.rb:23:in `<top (required)>' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/railtie.rb:39:in `require' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.1/lib/active_record/railtie.rb:39:in `block in <class:Railtie>' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/railties-4.1.1/lib/rails/railtie.rb:237:in `instance_exec' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/railties-4.1.1/lib/rails/railtie.rb:237:in `block in run_tasks_blocks' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/railties-4.1.1/lib/rails/railtie.rb:245:in `each' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/railties-4.1.1/lib/rails/railtie.rb:245:in `each_registered_block' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/railties-4.1.1/lib/rails/railtie.rb:237:in `run_tasks_blocks' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/railties-4.1.1/lib/rails/application.rb:361:in `block in run_tasks_blocks' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/railties-4.1.1/lib/rails/engine/railties.rb:13:in `each' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/railties-4.1.1/lib/rails/engine/railties.rb:13:in `each' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/railties-4.1.1/lib/rails/application.rb:361:in `run_tasks_blocks' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/railties-4.1.1/lib/rails/engine.rb:449:in `load_tasks' 
     /tmp/staged/app/Rakefile:6:in `<top (required)>' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/rake_module.rb:28:in `load' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/rake_module.rb:28:in `load_rakefile' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:689:in `raw_load_rakefile' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:94:in `block in load_rakefile' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:176:in `standard_exception_handling' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:93:in `load_rakefile' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:77:in `block in run' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:176:in `standard_exception_handling' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:75:in `run' 
     /tmp/staged/app/vendor/bundle/ruby/2.2.0/gems/rake-11.1.2/bin/rake:33:in `<top (required)>' 
     vendor/bundle/bin/rake:16:in `load' 
     vendor/bundle/bin/rake:16:in `<main>' 
###### WARNING: 
     You have not declared a Ruby version in your Gemfile. 
     To set your Ruby version add this line to your Gemfile: 
     ruby '2.2.3' 

Answer 1

ルックス：

gem 'sqlite3' # Use sqlite3 as the database for Active Record 

group :production do 
    gem 'rails_serve_static_assets' 
end 

これらは私が手にエラーが発生していますRAILS_ENV変数のように設定されていません。私はBluemixを使用していないので、そこで変数をエクスポートする方法がわからない。データベースが必要ない場合は、activerecordを含める必要はありません。 activerecordの削除方法の詳細については、threadを参照してください。