From: Joey Gibson <joey@...>
Date: 2003-12-24T04:41:56+09:00
Subject: Re: RubyGems and dependencies

On Wed, 24 Dec 2003, Francis Hwang wrote:

> 1. If I use RubyGems to document a dependency to another gem then am I
> correct in thinking it's not enough to simply have had that library
> installed -- I explicitly need that gem, right? I mean, Lafcadio
> depends on REXML and when I try to install the Lafcadio gem it tells
> me it can't find the REXML gem. REXML is already installed (I'm using
> Ruby 1.8 so it's part of the std library) but I'll need to install the
> REXML gem so that my Lafcadio gem will work, right?

This is the situation I tried to point out at RubyConf that I'd seen with
RedHat's rpm package manager. Namely that if I've already installed a
piece of software, without using the package manager, what will happen
when I try to install something else that _does_ use the package manager?
I don't really know how to solve it unless you can fake out the package
manager (gem-thingy) or have the gem producer provide some sort of test
that the gem-thingy can use at install time to check for the existence of
a piece of software that was installed manually. Maybe a filename/pathname
that it can check for as a last resort if the gem for a needed something
isn't found.

Joey