Cześć,
Windows 10 (niestety), Ruby v. 2.5.3, Rails v. 5.2.3
Dodałem w Gemfile :
gem ‘rspec-rails’, ‘~> 3.5’
gem ‘rswag’
Wykonałem Bundle install
Teraz wykonuję w katalogu aplikacji :
rails generate rspec:install
Dostaję error 
Traceback (most recent call last):
12: from bin/rails:4:in <main>' 11: from bin/rails:4:inrequire’
10: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-5.2.3/lib/rails/commands.rb:18:in <top (required)>' 9: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-5.2.3/lib/rails/command.rb:46:ininvoke’
8: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-5.2.3/lib/rails/command/base.rb:65:in perform' 7: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/thor-0.20.3/lib/thor.rb:387:indispatch’
6: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/thor-0.20.3/lib/thor/invocation.rb:126:in invoke_command' 5: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/thor-0.20.3/lib/thor/command.rb:27:inrun’
4: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-5.2.3/lib/rails/commands/generate/generate_command.rb:21:in perform' 3: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-5.2.3/lib/rails/command/actions.rb:14:inrequire_application_and_environment!’
2: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-5.2.3/lib/rails/command/actions.rb:22:in require_application!' 1: from C:/Ruby25-x64/lib/ruby/gems/2.5.0/gems/railties-5.2.3/lib/rails/command/actions.rb:22:inrequire’
C:/Users/user/ruby/awarie_pradu/config/application.rb:5:in <top (required)>': undefined local variable or methodconfig’ for main:Object (NameError)
Doczytałem się gdzieś, że trzeba zatrzymać SPRING - może pomoże. Niestety nie wiem jak to zrobić na Windows 10 (tfu). Chyba, że problem jest gdzie indziej. Pomożecie ?