From: Igal Koshevoy <igal@...>
Date: 2008-06-29T18:08:21+09:00
Subject: Re: Ruby 1.9.0/1.8.7/1.8.6/1.8.5 new releases (Security Fix)

Cheri Anaclerio wrote:
> Ok, I took the stow route and followed the steps below.  However, now 
> when I start the webrick server, Rubygems 0.9.4.1 can't be found even 
> though it is installed.  Looks like the directory I'm pointing to 
> doesn't know anything about Rubygems.  What can I do to fix this? 
> Thanks!  Cheri
>
> (See full trace by running task with --trace)
> Rails requires RubyGems >= 0.9.4. Please install RubyGems and try again: 
> http://rubygems.rubyforge.org
> [root@localhost cz]# yum install rubygems
>   
The problem is that the copy of RubyGems installed via Yum 
(/usr/bin/gem) is using your old interpreter (/usr/bin/ruby) and knows 
nothing about your new manually-compiled interpreter (/usr/local/bin/ruby).

The solution is to install RubyGems for the new interpreter, e.g.:

    wget http://rubyforge.org/frs/download.php/38646/rubygems-1.2.0.tgz
    tar xvfz rubygems-1.2.0.tgz
    cd rubygems-1.2.0
    sudo /usr/local/bin/ruby setup.rb --no-ri --no-rdoc
    sudo /usr/local/bin/gem install rake --no-ri --no-rdoc

Because the above changes the stowed directory structure, you'll want to 
restow it so that the new files are linked into /usr/local, e.g.:
   
    pushd /usr/local/stow; sudo stow --restow ruby-1.8.6p230smartleaf; popd

There's a way to make multiple Ruby interpreters share a copy of the 
installed gems by setting the GEM_HOME environmental variable. However, 
this seems like a bad idea and you're best off just installing new 
copies of the gems you need.

-igal