[Staging]: can't modify frozen Array (RuntimeError)

[1000miles]

We noticed that there is another bug on staging when checking the unicorn.stderr.log.

Probably related to middleware sine /config/application.rb:28 points to config.middleware.use(Rack::I18nLocaleSwitcher) in the backtrace.

Needs further investigation.

Error output

I, [2017-06-12T12:02:59.049054 #28155]  INFO -- : Refreshing Gem list
E, [2017-06-12T12:02:59.069661 #28155] ERROR -- : error reloading config_file=/var/apps/wheelmap/staging/current/config/unicorn.rb: can't modify frozen Array (RuntimeError)
E, [2017-06-12T12:02:59.069729 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/actionpack-4.1.15/lib/action_dispatch/middleware/stack.rb:112:in `push'
E, [2017-06-12T12:02:59.069756 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/actionpack-4.1.15/lib/action_dispatch/middleware/stack.rb:112:in `use'
E, [2017-06-12T12:02:59.069776 #28155] ERROR -- : /var/apps/wheelmap/staging/releases/20170612083357/config/application.rb:28:in `<class:Application>'
E, [2017-06-12T12:02:59.069795 #28155] ERROR -- : /var/apps/wheelmap/staging/releases/20170612083357/config/application.rb:13:in `<module:Wheelmap>'
E, [2017-06-12T12:02:59.069814 #28155] ERROR -- : /var/apps/wheelmap/staging/releases/20170612083357/config/application.rb:12:in `<top (required)>'
E, [2017-06-12T12:02:59.069832 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/activesupport-4.1.15/lib/active_support/dependencies.rb:247:in `require'
E, [2017-06-12T12:02:59.069852 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/activesupport-4.1.15/lib/active_support/dependencies.rb:247:in `block in require'
E, [2017-06-12T12:02:59.069874 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/activesupport-4.1.15/lib/active_support/dependencies.rb:232:in `load_dependency'
E, [2017-06-12T12:02:59.069893 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/activesupport-4.1.15/lib/active_support/dependencies.rb:247:in `require'
E, [2017-06-12T12:02:59.069912 #28155] ERROR -- : /var/apps/wheelmap/staging/releases/20170612083357/config/environment.rb:2:in `<top (required)>'
E, [2017-06-12T12:02:59.069936 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/activesupport-4.1.15/lib/active_support/dependencies.rb:247:in `require'
E, [2017-06-12T12:02:59.069954 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/activesupport-4.1.15/lib/active_support/dependencies.rb:247:in `block in require'
E, [2017-06-12T12:02:59.069976 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/activesupport-4.1.15/lib/active_support/dependencies.rb:232:in `load_dependency'
E, [2017-06-12T12:02:59.069997 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/activesupport-4.1.15/lib/active_support/dependencies.rb:247:in `require'
E, [2017-06-12T12:02:59.070017 #28155] ERROR -- : config.ru:8:in `block in <main>'
E, [2017-06-12T12:02:59.070035 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/rack-1.5.5/lib/rack/builder.rb:55:in `instance_eval'
E, [2017-06-12T12:02:59.070055 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/rack-1.5.5/lib/rack/builder.rb:55:in `initialize'
E, [2017-06-12T12:02:59.070078 #28155] ERROR -- : config.ru:1:in `new'
E, [2017-06-12T12:02:59.070096 #28155] ERROR -- : config.ru:1:in `<main>'
E, [2017-06-12T12:02:59.070118 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/unicorn-5.0.1/lib/unicorn.rb:46:in `eval'
E, [2017-06-12T12:02:59.070135 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/unicorn-5.0.1/lib/unicorn.rb:46:in `block in builder'
E, [2017-06-12T12:02:59.070155 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/unicorn-5.0.1/lib/unicorn/http_server.rb:752:in `call'
E, [2017-06-12T12:02:59.070171 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/unicorn-5.0.1/lib/unicorn/http_server.rb:752:in `build_app!'
E, [2017-06-12T12:02:59.070199 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/unicorn-5.0.1/lib/unicorn/http_server.rb:733:in `load_config!'
E, [2017-06-12T12:02:59.070218 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/unicorn-5.0.1/lib/unicorn/http_server.rb:314:in `join'
E, [2017-06-12T12:02:59.070238 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/gems/unicorn-5.0.1/bin/unicorn:126:in `<top (required)>'
E, [2017-06-12T12:02:59.070257 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/bin/unicorn:23:in `load'
E, [2017-06-12T12:02:59.070277 #28155] ERROR -- : /var/apps/wheelmap/staging/shared/bundle/ruby/2.2.0/bin/unicorn:23:in `<main>'
I, [2017-06-12T12:02:59.149335 #28155]  INFO -- : reaped #<Process::Status: pid 16107 exit 0> worker=0
I, [2017-06-12T12:02:59.208849 #17246]  INFO -- : worker=0 ready