Weird session-related bug in Chrome

[orenyk]

This is super bizarre, just reporting it for the record. Relevant log output here:

ls` WHERE 1=0ESC[0m
I, [2018-07-12T15:07:17.644802 #6746]  INFO -- :   Rendered reservations/_list_items_in_cart.html.erb (2.4ms)
I, [2018-07-12T15:07:17.646279 #6746]  INFO -- :   Rendered reservations/_cart_sidebar.html.erb (33.2ms)
I, [2018-07-12T15:07:17.646475 #6746]  INFO -- :   Rendered layouts/_sidebar.html.erb (44.6ms)
I, [2018-07-12T15:07:17.652662 #6746]  INFO -- :   Rendered layouts/_footer.html.erb (4.0ms)
I, [2018-07-12T15:07:17.653370 #6746]  INFO -- : Completed 200 OK in 739ms (Views: 182.4ms | ActiveRecord: 46.4ms)
F, [2018-07-12T15:07:17.655396 #6746] FATAL -- :   
F, [2018-07-12T15:07:17.658008 #6746] FATAL -- : NoMethodError (undefined method `default_proc=' for nil:NilClass):
F, [2018-07-12T15:07:17.658085 #6746] FATAL -- :   
F, [2018-07-12T15:07:17.658171 #6746] FATAL -- : activemodel (5.1.2) lib/active_model/errors.rb:455:in `block in without_default_proc'
activemodel (5.1.2) lib/active_model/errors.rb:454:in `tap'
activemodel (5.1.2) lib/active_model/errors.rb:454:in `without_default_proc'
activemodel (5.1.2) lib/active_model/errors.rb:423:in `marshal_dump'
actionpack (5.1.2) lib/action_dispatch/middleware/cookies.rb:503:in `dump'
actionpack (5.1.2) lib/action_dispatch/middleware/cookies.rb:503:in `serialize'
actionpack (5.1.2) lib/action_dispatch/middleware/cookies.rb:592:in `commit'
actionpack (5.1.2) lib/action_dispatch/middleware/cookies.rb:465:in `[]='
actionpack (5.1.2) lib/action_dispatch/middleware/session/cookie_store.rb:117:in `set_cookie'
rack (2.0.5) lib/rack/session/abstract/id.rb:363:in `commit_session'
rack (2.0.5) lib/rack/session/abstract/id.rb:234:in `context'
rack (2.0.5) lib/rack/session/abstract/id.rb:226:in `call'
actionpack (5.1.2) lib/action_dispatch/middleware/cookies.rb:613:in `call'
actionpack (5.1.2) lib/action_dispatch/middleware/callbacks.rb:26:in `block in call'
activesupport (5.1.2) lib/active_support/callbacks.rb:97:in `run_callbacks'
actionpack (5.1.2) lib/action_dispatch/middleware/callbacks.rb:24:in `call'
actionpack (5.1.2) lib/action_dispatch/middleware/debug_exceptions.rb:59:in `call'
actionpack (5.1.2) lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
railties (5.1.2) lib/rails/rack/logger.rb:36:in `call_app'
railties (5.1.2) lib/rails/rack/logger.rb:24:in `block in call'
activesupport (5.1.2) lib/active_support/tagged_logging.rb:69:in `block in tagged'
activesupport (5.1.2) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (5.1.2) lib/active_support/tagged_logging.rb:69:in `tagged'
railties (5.1.2) lib/rails/rack/logger.rb:24:in `call'
actionpack (5.1.2) lib/action_dispatch/middleware/remote_ip.rb:79:in `call'
request_store (1.3.2) lib/request_store/middleware.rb:9:in `call'
actionpack (5.1.2) lib/action_dispatch/middleware/request_id.rb:25:in `call'
rack (2.0.5) lib/rack/method_override.rb:22:in `call'
rack (2.0.5) lib/rack/runtime.rb:22:in `call'
activesupport (5.1.2) lib/active_support/cache/strategy/local_cache_middleware.rb:27:in `call'
actionpack (5.1.2) lib/action_dispatch/middleware/executor.rb:12:in `call'
actionpack (5.1.2) lib/action_dispatch/middleware/static.rb:125:in `call'
rack (2.0.5) lib/rack/sendfile.rb:111:in `call'
railties (5.1.2) lib/rails/engine.rb:522:in `call'
railties (5.1.2) lib/rails/railtie.rb:185:in `public_send'
railties (5.1.2) lib/rails/railtie.rb:185:in `method_missing'
/usr/local/rvm/gems/ruby-2.4.1/gems/passenger-5.1.8/src/ruby_supportlib/phusion_passenger/rack/thread_handler_extension.rb:97:in `process_request'
/usr/local/rvm/gems/ruby-2.4.1/gems/passenger-5.1.8/src/ruby_supportlib/phusion_passenger/request_handler/thread_handler.rb:152:in `accept_and_process_next_request'
/usr/local/rvm/gems/ruby-2.4.1/gems/passenger-5.1.8/src/ruby_supportlib/phusion_passenger/request_handler/thread_handler.rb:113:in `main_loop'
/usr/local/rvm/gems/ruby-2.4.1/gems/passenger-5.1.8/src/ruby_supportlib/phusion_passenger/request_handler.rb:416:in `block (3 levels) in start_threads'
/usr/local/rvm/gems/ruby-2.4.1/gems/passenger-5.1.8/src/ruby_supportlib/phusion_passenger/utils.rb:113:in `block in create_thread_and_abort_on_exception'

No idea what's going on, it appears to be fixed by clearing cookies so likely session related.