Ruby
Table of contents
Force a specific version of ruby
If you have things breaking because of Ruby v1.9 you can install ports with a special option to force another version of ruby to be used.make RUBY_VER=1.8 make RUBY_VER=1.8 install
This solved a lot of problems for me when portupgrade started upgrading to Ruby 1.9 automatically.
For instance rubygem-passenger depends on Ruby 1.9, but Redmine requires Ruby 1.8 to work.
Force a specific version of ruby gems
gem update --system 1.6.2
This fixed "Exception NoMethodError in PhusionPassenger : : ClassicRails : : ApplicationSpawner (undefined method `name' for "abstract":String)" for me.
Install a specific version of a gem
gem install rails -v=2.3.11
Phusion Passenger users guide
http://www.modrails.com/documentation/Users%20guide%20Apache.html