"undefined method `process_route'" when going to resque web ui

Question

I just started getting this error when going to the Resque web ui on my server. It does not happen locally, and it did not happen before some recent app changes/upgrades I made. I made no changes to the server itself. I could start reverting back changelists to see where it broke, but I upgraded a lot of gems at once so I have a hunch it'll be quite tricky.

So, any idea what would cause this or where it might be originating?

The path I'm going to is mydomain.com/app/resque

routes.rb

scope :path => "/app" do
  mount Resque::Server.new, :at => '/resque'
end

---

NoMethodError (undefined method `process_route' for #<Resque::Server:0x00000005dc95b0>):
  newrelic_rpm (3.3.4.1) lib/new_relic/agent/instrumentation/sinatra.rb:38:in `block in dispatch_with_newrelic'
  newrelic_rpm (3.3.4.1) lib/new_relic/agent/instrumentation/sinatra.rb:62:in `block in transaction_name'
  newrelic_rpm (3.3.4.1) lib/new_relic/agent/instrumentation/sinatra.rb:61:in `each'
  newrelic_rpm (3.3.4.1) lib/new_relic/agent/instrumentation/sinatra.rb:61:in `transaction_name'
  newrelic_rpm (3.3.4.1) lib/new_relic/agent/instrumentation/sinatra.rb:37:in `dispatch_with_newrelic'
  sinatra (1.0) lib/sinatra/base.rb:411:in `block in call!'
  sinatra (1.0) lib/sinatra/base.rb:566:in `instance_eval'
  sinatra (1.0) lib/sinatra/base.rb:566:in `block in invoke'
  sinatra (1.0) lib/sinatra/base.rb:566:in `catch'
  sinatra (1.0) lib/sinatra/base.rb:566:in `invoke'
  sinatra (1.0) lib/sinatra/base.rb:411:in `call!'
  sinatra (1.0) lib/sinatra/base.rb:399:in `call'
  rack (1.4.1) lib/rack/auth/basic.rb:25:in `call'
  sinatra (1.0) lib/sinatra/base.rb:979:in `block in call'
  sinatra (1.0) lib/sinatra/base.rb:1005:in `synchronize'
  sinatra (1.0) lib/sinatra/base.rb:979:in `call'
  actionpack (3.2.1) lib/action_dispatch/routing/mapper.rb:40:in `call'
  journey (1.0.3) lib/journey/router.rb:68:in `block in call'
  journey (1.0.3) lib/journey/router.rb:56:in `each'
  journey (1.0.3) lib/journey/router.rb:56:in `call'
  actionpack (3.2.1) lib/action_dispatch/routing/route_set.rb:589:in `call'
  omniauth (1.1.0) lib/omniauth/strategy.rb:177:in `call!'
  omniauth (1.1.0) lib/omniauth/strategy.rb:157:in `call'
  omniauth (1.1.0) lib/omniauth/builder.rb:48:in `call'
  newrelic_rpm (3.3.4.1) lib/new_relic/rack/browser_monitoring.rb:23:in `call'
  airbrake (3.0.9) lib/airbrake/rack.rb:27:in `call'
  warden (1.1.1) lib/warden/manager.rb:35:in `block in call'
  warden (1.1.1) lib/warden/manager.rb:34:in `catch'
  warden (1.1.1) lib/warden/manager.rb:34:in `call'
  actionpack (3.2.1) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
  rack (1.4.1) lib/rack/etag.rb:23:in `call'
  rack (1.4.1) lib/rack/conditionalget.rb:25:in `call'
  actionpack (3.2.1) lib/action_dispatch/middleware/head.rb:14:in `call'
  remotipart (1.0.2) lib/remotipart/middleware.rb:30:in `call'
  actionpack (3.2.1) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
  actionpack (3.2.1) lib/action_dispatch/middleware/flash.rb:242:in `call'
  rack (1.4.1) lib/rack/session/abstract/id.rb:205:in `context'
  rack (1.4.1) lib/rack/session/abstract/id.rb:200:in `call'
  actionpack (3.2.1) lib/action_dispatch/middleware/cookies.rb:338:in `call'
  activerecord (3.2.1) lib/active_record/query_cache.rb:64:in `call'
  activerecord (3.2.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:443:in `call'
  actionpack (3.2.1) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
  activesupport (3.2.1) lib/active_support/callbacks.rb:405:in `_run__2652675143263662148__call__736553824066291236__callbacks'
  activesupport (3.2.1) lib/active_support/callbacks.rb:405:in `__run_callback'
  activesupport (3.2.1) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
  activesupport (3.2.1) lib/active_support/callbacks.rb:81:in `run_callbacks'
  actionpack (3.2.1) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
  actionpack (3.2.1) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
  actionpack (3.2.1) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
  actionpack (3.2.1) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
  railties (3.2.1) lib/rails/rack/logger.rb:26:in `call_app'
  railties (3.2.1) lib/rails/rack/logger.rb:16:in `call'
  actionpack (3.2.1) lib/action_dispatch/middleware/request_id.rb:22:in `call'
  rack (1.4.1) lib/rack/methodoverride.rb:21:in `call'
  rack (1.4.1) lib/rack/runtime.rb:17:in `call'
  rack (1.4.1) lib/rack/lock.rb:15:in `call'
  rack-ssl (1.3.2) lib/rack/ssl.rb:27:in `call'
  rack-cache (1.2) lib/rack/cache/context.rb:136:in `forward'
  rack-cache (1.2) lib/rack/cache/context.rb:245:in `fetch'
  rack-cache (1.2) lib/rack/cache/context.rb:185:in `lookup'
  rack-cache (1.2) lib/rack/cache/context.rb:66:in `call!'
  rack-cache (1.2) lib/rack/cache/context.rb:51:in `call'
  airbrake (3.0.9) lib/airbrake/user_informer.rb:12:in `call'
  railties (3.2.1) lib/rails/engine.rb:479:in `call'
  railties (3.2.1) lib/rails/application.rb:220:in `call'
  railties (3.2.1) lib/rails/railtie/configurable.rb:30:in `method_missing'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/rack/request_handler.rb:96:in `process_request'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/abstract_request_handler.rb:513:in `accept_and_process_next_request'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/abstract_request_handler.rb:274:in `main_loop'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/rack/application_spawner.rb:206:in `start_request_handler'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/rack/application_spawner.rb:171:in `block in handle_spawn_application'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/utils.rb:479:in `safe_fork'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/rack/application_spawner.rb:166:in `handle_spawn_application'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/abstract_server.rb:357:in `server_main_loop'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/abstract_server.rb:206:in `start_synchronously'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/abstract_server.rb:180:in `start'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/rack/application_spawner.rb:129:in `start'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/spawn_manager.rb:253:in `block (2 levels) in spawn_rack_application'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/abstract_server_collection.rb:132:in `lookup_or_add'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/spawn_manager.rb:246:in `block in spawn_rack_application'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/abstract_server_collection.rb:82:in `block in synchronize'
  <internal:prelude>:10:in `synchronize'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/abstract_server_collection.rb:79:in `synchronize'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/spawn_manager.rb:244:in `spawn_rack_application'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/spawn_manager.rb:137:in `spawn_application'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/spawn_manager.rb:275:in `handle_spawn_application'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/abstract_server.rb:357:in `server_main_loop'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/lib/phusion_passenger/abstract_server.rb:206:in `start_synchronously'
  /usr/local/rvm/gems/ruby-1.9.3-p0@global/gems/passenger-3.0.11/helper-scripts/passenger-spawn-server:99:in `<main>'

Answer 1

You are combining a new version of new_relic with a very old version of sinatra. Run bundle update sinatra and make sure you have at least Sinatra 1.3.0, or try to downgrade the new_relic gem.

If you wonder why you have sinatra in your bundle at all: resque depends on it.

You could also add an explicite rule for a newer sinatra or an older new_relic to your Gemfile.

Answer 2

I resolved this by modifying my Gemfile to have the following lines:

gem 'sinatra', ">= 1.3.0"
gem 'newrelic_rpm'
gem 'resque'