nginx/passenger: Exception RangeError in PhusionPassenger::Railz::ApplicationSpawner (bignum too big to convert into `long')

Nasty.

I am running nginx+passenger on my OS X laptop and after getting the passenger module installed I got the following stacktrace in /opt/local/var/log/nginx/error.log:

*** Exception RangeError in PhusionPassenger::Railz::ApplicationSpawner (bignum too big to convert into `long') (process
 56051):
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/utils.rb:363:in `setgid'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/utils.rb:363:in `switch_to_user'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/utils.rb:328:in `lower_privilege'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/railz/application_spawner.rb:250:in
 `initialize_server'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/utils.rb:230:in `report_app_init_st
atus'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/railz/application_spawner.rb:237:in
 `initialize_server'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/abstract_server.rb:193:in `start_sy
nchronously'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/abstract_server.rb:162:in `start'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/railz/application_spawner.rb:213:in
 `start'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/spawn_manager.rb:261:in `spawn_rail
s_application'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/abstract_server_collection.rb:126:i
n `lookup_or_add'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/spawn_manager.rb:255:in `spawn_rail
s_application'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/abstract_server_collection.rb:80:in
 `synchronize'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/abstract_server_collection.rb:79:in
 `synchronize'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/spawn_manager.rb:254:in `spawn_rail
s_application'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/spawn_manager.rb:153:in `spawn_appl
ication'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/spawn_manager.rb:286:in `handle_spa
wn_application'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/abstract_server.rb:351:in `__send__
'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/abstract_server.rb:351:in `main_loo
p'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/lib/phusion_passenger/abstract_server.rb:195:in `start_sy
nchronously'
        from /opt/local/lib/ruby/gems/1.8/gems/passenger-2.2.4/bin/passenger-spawn-server:61

So, what's up?

The old switcheroo
Passenger implements User Switching which works around the age old problem that plagues most other scripting languages where they run in the same context as the web server they are accessed through.

The default behaviour is for rails apps to be started as the owner of config/environment.rb. There are however some points that should be noted:

• The owner of environment.rb must have read access to the rails application folder, and read/write access to the rails application logs folder.


• This feature is only available if nginx is started by root. This is the case on most nginx installations.


• Under no circumstances will applications be run as root. If environment.rb is owned as root or by an unknown user, then the rails application will run as the user specified by passenger_default_user.

In my case the project was owned by root so changing that to a local user fixed the problem.