Ruby & gems on 1.5.3

Official Hardware Classic Yún
1

Hi!
I wanted to test Sinatra http://www.sinatrarb.com/ on Arduino YUN. I have just updated to 1.5.3, moved filesystem to microSD card and run from shell:

opkg update
opkg install ruby
opkg install ruby-gems

and now try to install sinatra:

gem install sinatra

/usr/lib/ruby/1.9/rubygems.rb:31:in require': cannot load such file -- rbconfig (LoadError) from /usr/lib/ruby/1.9/rubygems.rb:31:in <top (required)>'
from internal:gem_prelude:1:in require' from <internal:gem_prelude>:1:in '

Running just gem command also returns this error.

Any hints?

2

You need to install other packages:

opkg update
opkg install ruby-core
opkg install ruby-enc
opkg install ruby-json