我有一个Rails 3.2.8应用程序，该应用程序在我的机器上运行良好，Postgres是ActivereCord的DB后端。但是，当我通过capistrano或通过rsync'ing我的项目将代码部署到EC2实例时，Rake不再列出任何db:任务：
$ rake -T
rake about # List versions of all Rails frameworks and the environment
rake assets:clean # Remove compiled assets
rake assets:precompile # Compile all the assets named in config.assets.precompile
rake doc:app # Generate docs for the app -- also available doc:rails, doc:guides, doc:plugins (options: TEMPLATE=/rdoc-t...
rake load_gml # Load GML source files into the environment database
rake log:clear # Truncates all *.log files in log/ to zero bytes
rake middleware # Prints out your Rack middleware stack
rake notes # Enumerate all annotations (use notes:optimize, :fixme, :todo for focus)
rake notes:custom # Enumerate a custom annotation, specify with ANNOTATION=CUSTOM
rake rails:template # Applies the template supplied by LOCATION=(/path/to/template) or URL
rake rails:update # Update configs and some other initially generated files (or use just update:configs, update:scripts, or u...
rake routes # Print out all defined routes in match order, with names.
rake secret # Generate a cryptographically secure secret key (this is typically used to generate a secret for cookie se...
rake stats # Report code statistics (KLOCs, etc) from the application
rake test # Runs test:units, test:functionals, test:integration together (also available: test:benchmark, test:profil...
rake test:recent # Run tests for {:recent=>"test:prepare"} / Test recent changes
rake test:single # Run tests for {:single=>"test:prepare"}
rake test:uncommitted # Run tests for {:uncommitted=>"test:prepare"} / Test changes since last checkin (only Subversion and Git)
rake time:zones:all # Displays all time zones, also available: time:zones:us, time:zones:local -- filter with OFFSET parameter,...
rake tmp:clear # Clear session, cache, and socket files from tmp/ (narrow w/ tmp:sessions:clear, tmp:cache:clear, tmp:sock...
rake tmp:create # Creates tmp directories for sessions, cache, sockets, and pids
rake -P还报告没有db:任务。
我猜这是某种依赖性问题，但是我看不到那是什么，因为我在bundler Gemfile中宣布所有宝石依赖性。Postgres 9.2.1已安装和工作，但是即使不是我不明白为什么耙子任务会消失。
感激地收到的有关发生的事情的任何线索！
，事实证明是愚蠢的简单：我已经从一个不使用ActivereCord的项目中复制了deploy.rb文件，因此我没有设置role db:。我仍然不确定为什么这意味着我的项目的rsync'ed副本也没有任何Rake db:任务，但是我不会再花任何循环来担心。