I have a problem with RubyMine 2017.3 EAP RuboCop Inspection. After upgrading from 2017.2 EAP said inspection stopped working for my projects.
I did some testing with Ruby 2.4 and 2.2 and uninstalling RuboCop and installing it from command line as well as uninstalling it and clicking 'Install RuboCop and enable inspection' in Event Log window, but none of it worked.
Finally, I determined that RuboCop inspection does not work unless line "gem 'rubocop'" is added to the project's Gemfile.
I haven't submitted YouTrack issue, because i'm not sure if this is a deliberate change or a bug, however, to my thinking Gemfile should contain gems that are necessary to run the program and mine will run just fine without RuboCop installed.
What are your thoughts one the issue