$ passenger-install-apache2-module --snippet
LoadModule passenger_module /home/redmine/.gem/ruby/gems/passenger-6.0.1/buildout/apache2/mod_passenger.so
<IfModule mod_passenger.c>
  PassengerRoot /home/redmine/.gem/ruby/gems/passenger-6.0.1
  PassengerDefaultRuby /usr/bin/ruby
</IfModule>