Passenger: cannot load such file rubygems/builder
There's seems to be problems with Ruby 2.0 and passenger as pointed on this reported issue:Passenger Ruby 2.0 issue
One of the proposed solutions (can be found on one of the comments there):
git clone https://github.com/FooBarWidget/passenger.gitcd passengergem build passenger.gemspecgem install passenger-3.9.5.rc3.gem (or type your actual built gem name)Edit:
To simplify the process a pre-release version (pointing to whatever latest RC version) can also be installed in the following fashion:
gem install passenger --pre