Error installing gems that use native extensions on Ubuntu, Ruby 1.9.2 via RVM

Question

I get an error while trying to install the ffi gem:

~ - 16:54>gem i ffi
Building native extensions.  This could take a while...
ERROR:  Error installing f         


        

Answer 1

Thanks @Tim Morris and @danv, your answers / comments helped. I adjusted for my setup, which is based more towards a superuser environment. Now this is what /usr/local/rvm/gems/ruby-1.9.2-p180/bin/rake looks like on my server:

require 'rubygems'

version = ">= 0"
ENV['GEM_HOME']=ENV['GEM_HOME'] || "/usr/local/rvm/gems/ruby-1.9.2-p180"
ENV['GEM_PATH']=ENV['GEM_PATH'] || "/usr/local/rvm/gems/ruby-1.9.2-p180:/usr/local/rvm/gems/ruby-1.9.2-p180@global"

if ARGV.first =~ /^_(.*)_$/ and Gem::Version.correct? $1 then
  version = $1
  ARGV.shift
end

gem 'rake', version
load Gem.bin_path('rake', 'rake', version)