Ruby Version Manager (RVM) Rocks (10 nov 10)
RVM
http://rvm.beginrescueend.com/
It rocks
Suppose you run 'irb' (interactive Ruby console) under ruby 1.8.7 with gems for Rails 3.0.3
IRB whines about something called 'readline' which is missing, and 'rails console' doesn't even run
See http://rvm.beginrescueend.com/packages/readline/
It says to do this
're-compile your ruby with readline support after obtaining the readline libraries'
rvm package install readline
rvm remove 1.8.7
rvm install 1.8.7 --with-readline-dir=$rvm_path/usr
No luck - but I found this at http://cjohansen.no/en/ruby/ruby_version_manager_ubuntu_and_openssl
sudo apt-get install libreadline5-dev
cd ~/.rvm/src/ruby-1.8.7-p302/ext/readline
ruby extconf.rb
make && make install
That did it - 'irb' and 'rails console' worked