Rails アプリで、rake gem を 0.9.2.2 から更新しました。10.0.3 へ、ラック 1.4.1 から 1.4.3 へ。
gem を更新する前にgit pushHeroku を実行すると、出力は次のようになります。
-----> Writing config/database.yml to read from DATABASE_URL
-----> Preparing app for Rails asset pipeline
Running: rake assets:precompile
rake aborted!
could not connect to server: Connection refused
Is the server running on host "127.0.0.1" and accepting
TCP/IP connections on port 5432?
Tasks: TOP => environment
(See full trace by running task with --trace)
Precompiling assets failed, enabling runtime asset compilation
Injecting rails31_enable_runtime_asset_compilation
Please see this article for troubleshooting help:
http://devcenter.heroku.com/articles/rails31_heroku_cedar#troubleshooting
（アセットのプリコンパイルの失敗には関係ありません。なぜそれが起こっているのか知っています）
しかし、gem を更新した後、Heroku にプッシュすると、次のエラーが発生します。
-----> Writing config/database.yml to read from DATABASE_URL
-----> Preparing app for Rails asset pipeline
Running: rake assets:precompile
rake aborted!
could not connect to server: Connection refused
Is the server running on host "127.0.0.1" and accepting
TCP/IP connections on port 5432?
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/postgresql_adapter.rb:1206:in `initialize'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/postgresql_adapter.rb:1206:in `new'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/postgresql_adapter.rb:1206:in `connect'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/postgresql_adapter.rb:329:in `initialize'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `new'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `postgresql_connection'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:309:in `new_connection'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:319:in `checkout_new_connection'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:241:in `block (2 levels) in checkout'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:236:in `loop'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:236:in `block in checkout'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:233:in `checkout'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:96:in `block in connection'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:95:in `connection'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_pool.rb:404:in `retrieve_connection'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_specification.rb:168:in `retrieve_connection'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/connection_adapters/abstract/connection_specification.rb:142:in `connection'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/model_schema.rb:308:in `clear_cache!'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.6/lib/active_record/railtie.rb:97:in `block (2 levels) in <class:Railtie>'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/callbacks.rb:418:in `_run__769451004690509272__prepare__527462282276125186__callbacks'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/callbacks.rb:405:in `__run_callback'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/callbacks.rb:385:in `_run_prepare_callbacks'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/callbacks.rb:81:in `run_callbacks'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.6/lib/action_dispatch/middleware/reloader.rb:74:in `prepare!'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.6/lib/action_dispatch/middleware/reloader.rb:48:in `prepare!'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/application/finisher.rb:47:in `block in <module:Finisher>'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/initializable.rb:30:in `instance_exec'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/initializable.rb:30:in `run'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/initializable.rb:55:in `block in run_initializers'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/initializable.rb:54:in `each'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/initializable.rb:54:in `run_initializers'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/application.rb:136:in `initialize!'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/railtie/configurable.rb:30:in `method_missing'
/tmp/build_15ju6av9wl7bb/config/environment.rb:5:in `<top (required)>'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/dependencies.rb:251:in `require'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/dependencies.rb:251:in `block in require'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/dependencies.rb:236:in `load_dependency'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/dependencies.rb:251:in `require'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/application.rb:103:in `require_environment!'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/application.rb:292:in `block (2 levels) in initialize_tasks'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.6/lib/sprockets/assets.rake:93:in `block (2 levels) in <top (required)>'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.6/lib/sprockets/assets.rake:60:in `block (3 levels) in <top (required)>'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.6/lib/sprockets/assets.rake:23:in `invoke_or_reboot_rake_task'
/tmp/build_15ju6av9wl7bb/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.6/lib/sprockets/assets.rake:29:in `block (2 levels) in <top (required)>'
Tasks: TOP => environment
(See full trace by running task with --trace)
Precompiling assets failed, enabling runtime asset compilation
Injecting rails31_enable_runtime_asset_compilation
Please see this article for troubleshooting help:
http://devcenter.heroku.com/articles/rails31_heroku_cedar#troubleshooting
ここで何が起こっているのですか？これは私が修正する必要があるものですか？アプリはまだ正常に動作しているようですが、少なくともエラーの原因を知りたいです。rake はバージョン 10.0.3 などでより冗長になったのでしょうか?