如何調試失敗的rake任務？

Question

我正在運行rake，但看不到任何導致它失敗的線索。 我想念什么？

undefined method `[]' for nil:NilClass
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.13/lib/active_record/railties/databases.rake:525:in `block (3 levels) in <top (required)>'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:246:in `call'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:246:in `block in execute'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:241:in `each'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:241:in `execute'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:184:in `block in invoke_with_call_chain'
/Users/me/.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:177:in `invoke_with_call_chain'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:205:in `block in invoke_prerequisites'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:203:in `each'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:203:in `invoke_prerequisites'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:183:in `block in invoke_with_call_chain'
/Users/me/.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:177:in `invoke_with_call_chain'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:170:in `invoke'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/activerecord-3.2.13/lib/active_record/railties/databases.rake:558:in `block (3 levels) in <top (required)>'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:246:in `call'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:246:in `block in execute'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:241:in `each'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:241:in `execute'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:184:in `block in invoke_with_call_chain'
/Users/me/.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:177:in `invoke_with_call_chain'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:205:in `block in invoke_prerequisites'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:203:in `each'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:203:in `invoke_prerequisites'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:183:in `block in invoke_with_call_chain'
/Users/me/.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:177:in `invoke_with_call_chain'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:205:in `block in invoke_prerequisites'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:203:in `each'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:203:in `invoke_prerequisites'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:183:in `block in invoke_with_call_chain'
/Users/me/.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:177:in `invoke_with_call_chain'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:205:in `block in invoke_prerequisites'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:203:in `each'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:203:in `invoke_prerequisites'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:183:in `block in invoke_with_call_chain'
/Users/me/.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:177:in `invoke_with_call_chain'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/task.rb:170:in `invoke'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/application.rb:143:in `invoke_task'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/application.rb:101:in `block (2 levels) in top_level'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/application.rb:101:in `each'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/application.rb:101:in `block in top_level'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/application.rb:110:in `run_with_threads'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/application.rb:95:in `top_level'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/application.rb:73:in `block in run'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/application.rb:160:in `standard_exception_handling'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/lib/rake/application.rb:70:in `run'
/Users/me/.rvm/gems/ruby-1.9.2-p320/gems/rake-10.0.4/bin/rake:33:in `<top (required)>'
/Users/me/.rvm/gems/ruby-1.9.2-p320/bin/rake:23:in `load'
/Users/me/.rvm/gems/ruby-1.9.2-p320/bin/rake:23:in `<main>'
/Users/me/.rvm/gems/ruby-1.9.2-p320/bin/ruby_executable_hooks:15:in `eval'
/Users/me/.rvm/gems/ruby-1.9.2-p320/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => db:test:load => db:test:purge


class AddSha2PasswordToAdminUsers < ActiveRecord::Migration
  def up
    add_column :admin_users, :md5_password, :string
    add_column :admin_users, :password_salt, :string

    Rake::Task['tmp:sessions:clear'].invoke

    AdminUser.update_all("md5_password=encrypted_password")
    AdminUser.update_all("encrypted_password=null")
  end

  def down
    remove_column :admin_users, :md5_password, :password_salt
  end

end

Answer 1

糾正config / database.yml中的錯誤為我解決了此問題。