From: Lloyd Zusman <ljz@...>
Date: 2005-06-21T08:23:06+09:00
Subject: Re: Confusion about gems and non-gems working together.

Chad Fowler <chadfowler@gmail.com> writes:

> Hi Lloyd!

Hi Chad! :)


> [ ... ]
>
>> I now think that I might have figured out what is going on for me:
>> 
>> In all the cases where I had these problems, I had non-gem installs of
>> earlier versions of the packages.  In many cases, it seems like code
>> inside of files associated with these earlier versions would get
>> executed instead of the code that the newer gem would use.
>> 
>> [ ... ]
>>
>> Has anyone else experienced anything like this?  If so, how did you
>> handle it?
>> 
>
> I haven't, but I don't use non-gem libs much anymore.  Could you give
> a specific example?  I think it might be instructive.  As long as the
> gem version of the library is before the non-gem version in the load
> path (which it should be), you should get the gem version of the lib.
> Since that's obviously not the way it's working for you, it would be
> great to hear some specifics.

Well, prior to receiving this message of yours, I had fixed all
occurrences of this problem by manually deleting the non-gem versions of
the offending packages.  Therefore, it's hard to reproduce now.

However, one case I recall clearly where I had consistent problems was
when I first installed the gem version of wee.  I had installed an
earlier non-gem version, and until I deleted that, I couldn't even get
the gem install to work.  My messages about this problem should be in
the archives of this mailing list, although that was before I thought of
the possibility that the non-gem version might be interfering with the
gem.


>> [ ... ]  If so, how can I find out what is the exhaustive list of
>> files and directories to remove for a given package?
>> 
>
> That's part of the problem pre-gems.  There's no nice, repeatable way
> to do this.  If you've got the original tar file lying around, you can
> look at it's contents and remove files that seem to have been
> installed by it.  [ ... ]

Yes, that's what I have done during the manual uninstalls that I
mentioned above.

> [ ... ]  Even then, you'll probably want to use a checksum of some
> sort just in case installations of later libs over wrote files of the
> same name (which you might still be depending on).

I didn't do that in this case.  I hope I don't get bit.


>> This brings up a suggestion: could the gem installer check for
>> previously installed non-gem versions of the package in question, and
>> then ask the user if he/she wants to optionally delete them as part of
>> the gem install?  [ ... ]
>> 
>
> I'll add it to our list.  It would be hard to do cleanly and reliably,
> but as an optional user-verifiable setting, it wouldn't be too
> terribly evil.

As I mentioned earlier, I would find it amply useful, and I'm sure that
I'm not the only person.


-- 
 Lloyd Zusman
 ljz@asfast.com
 God bless you.