From: Curt Hibbs <curt@...>
Date: 2003-12-24T22:40:42+09:00
Subject: Re: RubyGems and dependencies

Phil Tomson wrote:
> Joey Gibson  <joey@joeygibson.com> wrote:
> >
> >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.
>
> Something like:
>
> #let's see if they've already got rexml:
> begin
>   require 'rexml'
> rescue MissingPackage #or whatever it's really called
>   #it's really not here, so go look for one to download
>   ...
> else
>   #it is here already, maybe check out the version somehow
>   #otherwise everything should be OK
> end

This is too simple. RubyGems should also check that the proper version is
installed.

I think that RubyGems should optionally allow the user to inform it of a
manual installation when a gem is not found, prompting the user for the need
information (like version number installed). That particular gem would then
be entered into its gem-database as having been installed manually for
future use.

Correspondingly, there should be an option to remove such a
manual-installation-entry from the RubyGems database.

Curt