耙子流产了! 用于ActiveRecord :: Base的未定义方法`migration_error =’:Class

我正在使用Ruby on Rails开发项目直到现在我使用Rails 4并且在我遇到gem的无能力问题之前一切都很好。 我决定回滚到Rails 3,更改我的Gemfile,删除Gemfile.lock,所有rails安装和railties。 然后我运行bundle install并安装了Rails 3.2.13。 但是现在当我运行rake db时:创建一切仍然很好。 当我运行rake db:migrate问题开始时:

JeffreeBook:llvoo kristijonas$ rake db:migrate WARNING: Nokogiri was built against LibXML version 2.8.0, but has dynamically loaded 2.7.8 rake aborted! undefined method `migration_error=' for ActiveRecord::Base:Class /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activerecord-3.2.13/lib/active_record/dynamic_matchers.rb:55:in `method_missing' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activerecord-3.2.13/lib/active_record/railtie.rb:66:in `block (3 levels) in ' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activerecord-3.2.13/lib/active_record/railtie.rb:65:in `each' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activerecord-3.2.13/lib/active_record/railtie.rb:65:in `block (2 levels) in ' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:43:in `block in run_load_hooks' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:42:in `each' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:42:in `run_load_hooks' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activerecord-3.2.13/lib/active_record/base.rb:720:in `' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/gems/activerecord-3.2.13/lib/active_record/railties/databases.rake:25:in `block (2 levels) in ' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/bin/ruby_noexec_wrapper:14:in `eval' /Users/kristijonas/.rvm/gems/ruby-1.9.3-p448@fashion/bin/ruby_noexec_wrapper:14:in `' Tasks: TOP => db:migrate => db:load_config (See full trace by running task with --trace) JeffreeBook:llvoo kristijonas$ 

如何解决它?db config一切都很好

将Rails 4项目滚回Rails 3会导致此错误。 从config/environments/development.rb删除以下行修复了此问题:

 config.active_record.migration_error = :page_load 

尝试:

 bundle exec rake db:migrate