Phusion Passenger cannot start Rails application - ruby-on-rails

Question

Any help would be greatly appreciated. I'm trying to run basic Rails apps on my server.
I'm running Ubuntu and nginx. Ideally I'd like to be able to still run php apps so nginx+Phusion seems like the way to go.
A source file that the application requires, is missing.
It is possible that you didn't upload your application files correctly. Please check whether all your application files are uploaded.
A required library may not installed. Please install all libraries that this application requires.
Further information about the error may have been written to the application's log file. Please check it in order to analyse the problem.
Error message:
no such file to load -- bundler
Exception class:
LoadError
0 /usr/lib/ruby/1.8/rubygems/custom_require.rb 31 in gem_original_require'
1 /usr/lib/ruby/1.8/rubygems/custom_require.rb 31 inrequire'
2 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/utils.rb 325 in prepare_app_process'
3 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/rack/application_spawner.rb 156 ininitialize_server'
4 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/utils.rb 563 in report_app_init_status'
5 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/rack/application_spawner.rb 154 ininitialize_server'
6 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/abstract_server.rb 204 in start_synchronously'
7 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/abstract_server.rb 180 instart'
8 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/rack/application_spawner.rb 129 in start'
9 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/spawn_manager.rb 253 inspawn_rack_application'
10 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/abstract_server_collection.rb 132 in lookup_or_add'
11 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/spawn_manager.rb 246 inspawn_rack_application'
12 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/abstract_server_collection.rb 82 in synchronize'
13 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/abstract_server_collection.rb 79 insynchronize'
14 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/spawn_manager.rb 244 in spawn_rack_application'
15 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/spawn_manager.rb 137 inspawn_application'
16 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/spawn_manager.rb 275 in handle_spawn_application'
17 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/abstract_server.rb 357 insend'
18 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/abstract_server.rb 357 in server_main_loop'
19 /var/lib/gems/1.8/gems/passenger-3.0.19/lib/phusion_passenger/abstract_server.rb 206 instart_synchronously'
20 /var/lib/gems/1.8/gems/passenger-3.0.19/helper-scripts/passenger-spawn-server 99

Answer 1

It seems like you installed passenger to your system ruby installation and not for the 1.9.3-p374 version via rvm. Try to follow the below steps:
rvm use 1.9.3-p374
gem install bundler passenger
passenger-install-apache2-module
Then use the instructions from the last command and configure your apache with them. Additionally, go to the project directory and do
rvm use 1.9.3-p374
bundle install
That should do the trick.