我正在进行 Rails 升级，并且能够成功升级到4.1.16
现在跳转到4.2... 能够成功运行bundle update，但是当我尝试运行我的规范时，我得到了SystemStackError如下所示的不足：
//home/vagrant/.rvm/gems/ruby-2.2.3/gems/arel-6.0.4/lib/arel/visitors/reduce.rb:14:in `rescue in visit': stack level too deep (SystemStackError)
from /home/vagrant/.rvm/gems/ruby-2.2.3/gems/arel-6.0.4/lib/arel/visitors/reduce.rb:13:in `visit'
from /home/vagrant/.rvm/gems/ruby-2.2.3/gems/arel-6.0.4/lib/arel/visitors/to_sql.rb:241:in `block in visit_Arel_Nodes_SelectCore'
from /home/vagrant/.rvm/gems/ruby-2.2.3/gems/arel-6.0.4/lib/arel/visitors/to_sql.rb:240:in `each'
from /home/vagrant/.rvm/gems/ruby-2.2.3/gems/arel-6.0.4/lib/arel/visitors/to_sql.rb:240:in `each_with_index'
from /home/vagrant/.rvm/gems/ruby-2.2.3/gems/arel-6.0.4/lib/arel/visitors/to_sql.rb:240:in `visit_Arel_Nodes_SelectCore'
from /home/vagrant/.rvm/gems/ruby-2.2.3/gems/arel-6.0.4/lib/arel/visitors/to_sql.rb:210:in `block in visit_Arel_Nodes_SelectStatement'
from /home/vagrant/.rvm/gems/ruby-2.2.3/gems/arel-6.0.4/lib/arel/visitors/to_sql.rb:209:in `each'
from /home/vagrant/.rvm/gems/ruby-2.2.3/gems/arel-6.0.4/lib/arel/visitors/to_sql.rb:209:in `inject'
... 9265 levels...
from /home/vagrant/.rvm/gems/ruby-2.2.3/bin/rspec:23:in `load'
from /home/vagrant/.rvm/gems/ruby-2.2.3/bin/rspec:23:in `<main>'
from /home/vagrant/.rvm/gems/ruby-2.2.3/bin/ruby_executable_hooks:15:in `eval'
from /home/vagrant/.rvm/gems/ruby-2.2.3/bin/ruby_executable_hooks:15:in `<main>'
我正在尝试找出这里需要更改/更新的内容，谢谢。
PS：Ruby版本是2.2.3
#Update： 我在之前的堆栈跟踪中犯了一个错误，是错误的，我现在已经更新了。
#Update（03/16）：
这似乎是由设计引起的......我设法将错误追溯到以下行config/initializers/devise.rb：
require 'devise/orm/active_record'