Cannot run Unicorn with Ruby 2.0

Question

On my ubuntu machine, I can run unicorn on ruby 1.9.3, however, it does not seem to work with ruby 2.0. Any idea why?

root@dev:/home/karan# rvm use 1.9
Using /usr/local/rvm/gems/ruby-1.9.3-p429
root@dev:/home/karan# unicorn -v
unicorn v4.6.3
root@dev:/home/karan# rvm use 2.0
Using /usr/local/rvm/gems/ruby-2.0.0-p195
root@dev:/home/karan# unicorn -v
/usr/local/rvm/rubies/ruby-2.0.0-p195/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require': cannot load such file -- unicorn/launcher (LoadError)
        from /usr/local/rvm/rubies/ruby-2.0.0-p195/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require'
        from /usr/bin/unicorn:3:in `<main>'

Answer 1

Try reinstalling the gem with 2.0.0.

The problem must have been caused by the fact the gem was installed in 1.9.3.