RuntimeError:无法修改冻结的数组

Question

我将Ruby on Rails应用程序更新为Ruby on Rails 5.1.4.当我运行我的测试时,每个测试都会返回以下错误:

An error occurred while loading {path to specific spec file}
Failure/Error: require File.expand_path('../../config/environment', __FILE__)

RuntimeError:
  can't modify frozen Array
# ./config/environment.rb:6:in `<top (required)>'
# ./spec/rails_helper.rb:4:in `<top (required)>'

我该如何解决这个问题？

编辑:

我正在从5.0.0.1更新到5.1.4.