Ruby on rails 未定义的方法`最新的#迁移'；零级：零级

你知道这是什么问题吗

rake gems:install --trace
rake/rdoctask is deprecated.  Use rdoc/task instead (in RDoc 2.4.2+)
DEPRECATION WARNING: Rake tasks in vendor/plugins/community_engine/tasks, vendor/plugins/community_engine/tasks, vendor/plugins/community_engine/tasks, vendor/plugins/delayed_job/tasks, vendor/plugins/prepop/tasks, vendor/plugins/redhillonrails_core/tasks, and vendor/plugins/smart_log/tasks are deprecated. Use lib/tasks instead. (called from /Library/Ruby/Gems/1.8/gems/rails-2.3.8/lib/tasks/rails.rb:10)
** Invoke gems:install (first_time)
** Invoke gems:base (first_time)
** Execute gems:base
** Invoke environment (first_time)
** Execute environment
Cloning dev plugins:
rake aborted!
undefined method `latest_migration' for nil:NilClass
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.8/lib/active_support/whiny_nil.rb:52:in `method_missing'
/users/umairejaz/Projects/dev-presaletoday/vendor/plugins/community_engine/lib/community_engine.rb:16:in `check_for_pending_migrations'
/users/umairejaz/Projects/dev-presaletoday/vendor/plugins/community_engine/config/boot.rb:8
/Library/Ruby/Site/1.8/rubygems/custom_require.rb:36:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/custom_require.rb:36:in `require'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:156:in `require_without_desert'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:521:in `new_constants_in'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:156:in `require_without_desert'
/Library/Ruby/Gems/1.8/gems/desert-0.5.4/lib/desert/ruby/object.rb:8:in `require'
/Library/Ruby/Gems/1.8/gems/desert-0.5.4/lib/desert/ruby/object.rb:32:in `__each_matching_file'
/Library/Ruby/Gems/1.8/gems/desert-0.5.4/lib/desert/ruby/object.rb:7:in `require'
/users/umairejaz/Projects/dev-presaletoday/config/environment.rb:54
/Library/Ruby/Site/1.8/rubygems/custom_require.rb:36:in `gem_original_require'
/Library/Ruby/Site/1.8/rubygems/custom_require.rb:36:in `require'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:156:in `require'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:521:in `new_constants_in'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:156:in `require'
/Library/Ruby/Gems/1.8/gems/rails-2.3.8/lib/tasks/misc.rake:4
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:205:in `call'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:205:in `execute'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:200:in `each'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:200:in `execute'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:158:in `invoke_with_call_chain'
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:144:in `invoke'
/Library/Ruby/Gems/1.8/gems/rails-2.3.8/lib/tasks/gems.rake:17
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:205:in `call'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:205:in `execute'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:200:in `each'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:200:in `execute'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:158:in `invoke_with_call_chain'
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize'
/Library/Ruby/Gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain'

---

您确定已正确安装CommunityEngine吗

我在这里看到：

newest_ce_migration = Desert::Manager.find_plugin('community_engine').latest_migration

它试图找到您的插件并在其上调用最新的_迁移方法，但它什么也找不到，并在nil上尝试这样做