Have you recently updated the gem from < 1.9.0? If you look at the Changelog note that it recently switched to using zeitwerk for loading.
This means that if you are doing e.g. require "dry/validation/contract" you should remove that and only do require "dry/validation", as that will set up the zeitwerk gem loader for all other constants.
Have the same issue: running a test and using binding.pry in a controller. Everything fine if i let the test run its course or run rails console.
I have tried to require some parts in rails_helper.rb and it solves ClassInterface, but there are other modules that fail down the line
For example, third in line is NameError: uninitialized constant Dry::Schema::Messages::Abstract - it fails in case requiring message_compiler