ArgumentError (A copy of Api::V1 has been removed from the module tree but is still active!)

Question

I have been struggling with this problem for days now. I have an app for which I am building some APIs and the above mentioned error always crashes my app when running for the first time. The error vanishes on reloading the app but it's annoying none the less. Here are some similar questions asked about this error:

A copy of xxx has been removed from the module tree but is still active

ArgumentError: A copy of ApplicationController has been removed from the module tree but is still active

These both links don't address the issue I'm facing. Here's the complete stack trace:

ArgumentError (A copy of Api::V1 has been removed from the module tree but is still active!):
activesupport (5.1.4) lib/active_support/dependencies.rb:495:in `load_missing_constant'
activesupport (5.1.4) lib/active_support/dependencies.rb:202:in `const_missing'
activesupport (5.1.4) lib/active_support/inflector/methods.rb:271:in `const_get'
activesupport (5.1.4) lib/active_support/inflector/methods.rb:271:in `block in constantize'
activesupport (5.1.4) lib/active_support/inflector/methods.rb:267:in `each'
activesupport (5.1.4) lib/active_support/inflector/methods.rb:267:in `inject'
activesupport (5.1.4) lib/active_support/inflector/methods.rb:267:in `constantize'
activesupport (5.1.4) lib/active_support/dependencies.rb:582:in `get'
activesupport (5.1.4) lib/active_support/dependencies.rb:613:in `constantize'
actionpack (5.1.4) lib/action_dispatch/http/request.rb:85:in `controller_class_for'
actionpack (5.1.4) lib/action_dispatch/http/parameters.rb:99:in `binary_params_for?'
actionpack (5.1.4) lib/action_dispatch/http/parameters.rb:90:in `set_binary_encoding'
actionpack (5.1.4) lib/action_dispatch/http/parameters.rb:67:in `path_parameters='
actionpack (5.1.4) lib/action_dispatch/journey/router.rb:48:in `block in serve'
actionpack (5.1.4) lib/action_dispatch/journey/router.rb:33:in `each'
actionpack (5.1.4) lib/action_dispatch/journey/router.rb:33:in `serve'
actionpack (5.1.4) lib/action_dispatch/routing/route_set.rb:834:in `call'
bullet (5.7.5) lib/bullet/rack.rb:14:in `call'
warden (1.2.7) lib/warden/manager.rb:36:in `block in call'
warden (1.2.7) lib/warden/manager.rb:35:in `catch'
warden (1.2.7) lib/warden/manager.rb:35:in `call'
rack (2.0.5) lib/rack/etag.rb:25:in `call'
rack (2.0.5) lib/rack/conditional_get.rb:25:in `call'
rack (2.0.5) lib/rack/head.rb:12:in `call'
rack (2.0.5) lib/rack/session/abstract/id.rb:232:in `context'
rack (2.0.5) lib/rack/session/abstract/id.rb:226:in `call'
actionpack (5.1.4) lib/action_dispatch/middleware/cookies.rb:613:in `call'
activerecord (5.1.4) lib/active_record/migration.rb:556:in `call'
actionpack (5.1.4) lib/action_dispatch/middleware/callbacks.rb:26:in `block in call'
activesupport (5.1.4) lib/active_support/callbacks.rb:97:in `run_callbacks'
actionpack (5.1.4) lib/action_dispatch/middleware/callbacks.rb:24:in `call'
actionpack (5.1.4) lib/action_dispatch/middleware/executor.rb:12:in `call'
airbrake (7.3.0) lib/airbrake/rack/middleware.rb:52:in `call'
actionpack (5.1.4) lib/action_dispatch/middleware/debug_exceptions.rb:59:in `call'
web-console (3.6.1) lib/web_console/middleware.rb:135:in `call_app'
web-console (3.6.1) lib/web_console/middleware.rb:30:in `block in call'
web-console (3.6.1) lib/web_console/middleware.rb:20:in `catch'
web-console (3.6.1) lib/web_console/middleware.rb:20:in `call'
actionpack (5.1.4) lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
railties (5.1.4) lib/rails/rack/logger.rb:36:in `call_app'
railties (5.1.4) lib/rails/rack/logger.rb:24:in `block in call'
activesupport (5.1.4) lib/active_support/tagged_logging.rb:69:in `block in tagged'
activesupport (5.1.4) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (5.1.4) lib/active_support/tagged_logging.rb:69:in `tagged'
railties (5.1.4) lib/rails/rack/logger.rb:24:in `call'
sprockets-rails (3.2.1) lib/sprockets/rails/quiet_assets.rb:13:in `call'
actionpack (5.1.4) lib/action_dispatch/middleware/remote_ip.rb:79:in `call'
actionpack (5.1.4) 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 (5.1.4) lib/active_support/cache/strategy/local_cache_middleware.rb:27:in `call'
actionpack (5.1.4) lib/action_dispatch/middleware/executor.rb:12:in `call'
actionpack (5.1.4) lib/action_dispatch/middleware/static.rb:125:in `call'
rack (2.0.5) lib/rack/sendfile.rb:111:in `call'
rack-mini-profiler (1.0.0) lib/mini_profiler/profiler.rb:285:in `call'
webpacker (3.4.3) lib/webpacker/dev_server_proxy.rb:18:in `perform_request'
rack-proxy (0.6.4) lib/rack/proxy.rb:57:in `call'
railties (5.1.4) lib/rails/engine.rb:522:in `call'
puma (3.11.4) lib/puma/configuration.rb:225:in `call'
puma (3.11.4) lib/puma/server.rb:632:in `handle_request'
puma (3.11.4) lib/puma/server.rb:446:in `process_client'
puma (3.11.4) lib/puma/server.rb:306:in `block in run'
puma (3.11.4) lib/puma/thread_pool.rb:120:in `block in spawn_thread'

Answer 1

As the stack trace suggests, this is a dependancy clash of the app with ActiveSupport. I recommend using the gem bootsnap. Bootsnap overrides ActiveSupport::Dependencies which is causing the issue in the first place. It also improves the app's load time which is actually what it is designed for. From Bootsnap documentation:

ActiveSupport::Dependencies.{autoloadable_module?,load_missing_constant,depend_on} are overridden to eliminate scans of ActiveSupport::Dependencies.autoload_paths.