我最近从v4.3升级到Rails 5.1，现在运行测试时出现此错误：
An error occurred while loading
./spec/controllers/admin/capacity_charges_controller_spec.rb.
Failure/Error: require File.expand_path('../../config/environment', __FILE__)
RuntimeError:
can't modify frozen Array
我得到每个测试文件。触发错误的行来自rails_helper。我检查了rails 5.1样品回购，我们的版本没有什么大不相同。
完整的堆栈跟踪是：
RuntimeError:
can't modify frozen Array
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/actionpack-5.1.0/lib/action_dispatch/middleware/stack.rb:74:in `insert'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/actionpack-5.1.0/lib/action_dispatch/middleware/stack.rb:74:in `insert'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/actionpack-5.1.0/lib/action_dispatch/middleware/stack.rb:81:in `insert_after'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/request_store-1.3.2/lib/request_store/railtie.rb:5:in `block in <class:Railtie>'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/railties-5.1.0/lib/rails/initializable.rb:30:in `instance_exec'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/railties-5.1.0/lib/rails/initializable.rb:30:in `run'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/railties-5.1.0/lib/rails/initializable.rb:59:in `block in run_initializers'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/railties-5.1.0/lib/rails/initializable.rb:58:in `run_initializers'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/railties-5.1.0/lib/rails/application.rb:353:in `initialize!'
# ./config/environment.rb:5:in `<top (required)>'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:292:in `require'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:292:in `block in require'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:258:in `load_dependency'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:292:in `require'
# ./spec/rails_helper.rb:12:in `<top (required)>'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:292:in `require'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:292:in `block in require'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:258:in `load_dependency'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:292:in `require'
# ./spec/controllers/admin/capacity_charges_controller_spec.rb:3:in `<top (required)>'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:286:in `load'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:286:in `block in load'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:258:in `load_dependency'
# /Users/jeremynagel/.rvm/gems/[email protected]_EnergyLink/gems/activesupport-5.1.0/lib/active_support/dependencies.rb:286:in `load'
事实证明这是由堆栈跟踪中更高的测试失败引起的。很难看出根本原因是什么，因为控制台中有这么多。如果你遇到这个问题，我建议使用--fail-fast，这样你就不会被重复的错误消息所淹没。然后检查第一个错误是什么。
对我来说，这是从版本4到5的FactoryBot更新。我没有看到弃用警告，因为我跳过了版本：
DEPRECATION WARNING: Static attributes will be removed in FactoryBot 5.0.
有时，如果Ruby类中的类名继承错误，也会引发此异常。请记住，控制器，模型等都是Ruby中的常量。
这是我遇到的情况的最佳例子。实际语法可能已关闭，但这是导致我的问题的概念。
module Admin
class BaseController < ::ApplicationController
...
end
end
# throws error, referencing constant that does not exist.
# Should be < ::Admin::BaseController
class OtherController < ::BaseController
end
和其他人一样，我的整个rspec套件都会因为错误can't modify a frozen Array而失败，这本身就不是一个非常有用的堆栈跟踪本身。
希望这可以节省其他人花费数小时追捕其他一切！
当我得到类似堆栈跟踪的相同错误时，它帮助我修复了工厂中的语法错误。
我尝试从Rails 3更新到Rails 5.我只是设置config.eager_load选项，它有所帮助。要么是false，要么是true。请不要nil
在我的情况下，最近的rails_admin需要一些补充
RuntimeError：未添加RailsAdmin所需的中间件 要解决这个问题，请添加
config.middleware.use ActionDispatch::Flashto config / application.rb。
然后所有的rspec再次变绿了。
在我的情况下，这是由于我错过了解决的git冲突消息（像>>>> ... === ... <<<<这样），所以当Rspec尝试加载该类时出现语法错误。
在这种情况下，--fail-fast命令行选项没有帮助，因为调用堆栈中的错误发生率更高，但您可以通过运行任何单个spec文件来查看实际错误。
检查您的测试数据库是否是最新的。
rake db：test：prepare。