# File railties/lib/initializer.rb, line 309 def load_observers if @gems_dependencies_loaded && configuration.frameworks.include?(:active_record) ActiveRecord::Base.instantiate_observers end end
observers and custom initializers aren’t loaded if any gems are missing -
current behaviour isn’t great - as it’s not intuitive - and you get no warning.
here’s a lighthouse ticket i created a while ago about this.