I think this issue is also affecting Rails 6.1 on the system ruby/ruby- bundler packages. Testing on the latest Ubuntu Focal stable packages:
$ sudo gem install rails -v 6.1.1 $ rails new my-app $ cd my-app && bundle exec rails db:setup rails aborted! TypeError: superclass mismatch for class Command The workaround mentioned above involving adding "gem 'thor', '~> 0.20.3'" to the Gemfile doesn't work anymore as of Rails 6.1 because railties 6.1 now specifies thor ~> 1.0. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1885424 Title: Create package for Thor 1.0.1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ruby-thor/+bug/1885424/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs