From: Ruby Newbee <rubynewbee@...>
Date: 2010-01-11T16:08:26+09:00
Subject: Re: roll back to last command in irb

On Sun, Jan 10, 2010 at 5:40 PM, Marvin Gülker <sutniuq@gmx.net> wrote:

>
> Did you compile Ruby yourself? If so, install one of the packages
> libreadline5-dev or libreadline6-dev and then compile again.
>

Yes coz my ubuntu doesn't have a ruby pre-installed, so I got the
source from ruby-lang.org and installed it by hand.
I have resolved the problem following your suggestion. Thanks.