From: Roger Pack <rogerdpack@...>
Date: 2009-12-05T02:12:42+09:00
Subject: [ruby-core:27041] Re: [Bug #2433] Ruby gem update --system /gem 	install [any_gem_name] ERROR

install [gem_name] I always got the below error:
> [code]
> serge@serge-laptop:~$ sudo gem install heroku
> ERROR: �Error installing heroku:
> � � � �invalid gem format for /usr/lib/ruby/gems/1.8/cache/heroku-1.4.gem

Have you tried gem fetch+unpack heroku? Can you install it locally
from a .gem file?
-r