Re: Installation failure caused by CDPATH environment variable

From: David Kastrup <dak@gnu.org>
Date: Jul 12, 2007, 07:51 UTC
Message-ID: <86sl7u12m3.fsf@lola.quinscape.zz>
In-Reply-To: <Pine.LNX.4.64.0707111807470.4516@racer.site>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

Show 9 quoted lines

> On Wed, 11 Jul 2007, Wincent Colaiuta wrote:
>
>> [describes the typical CDPATH problem]
>
> You exported CDPATH.  You're guaranteed to run into problems with that.  I 
> doubt that your patch catches all problems in git, and even if we tried to 
> avoid breakage, you can only do so much about that.
>
> It is _wrong_ to export CDPATH.

But it is not our job to educate people about that. So I'd just add something like

[ "X" = "X$CDPATH" ] || unset CDPATH # ignore braindamaged exports

to the top of possibly affected scripts and be done.

After the first few dozen bug reports (which are just the tip of an iceberg of people who say "git is crap and fails in strange ways") you just recognize that you should just make that somebody else's problem.

I've done my fair amount of such educational tasks myself with packages of mine. It just gets you annoyed more and more each time, it is tedious, it gets people get a bad opinion of both your software _and_ your person (try being friendly after the 20th actually technically completely unnecessary such request, while basically explaining that you won't fix it because it is a Darwinian trap for stupid people and you want evolution to run its course).

A one-liner that makes this somebody else's problem (if at all) is worth its weight in gold.

Trust me on that.

My personal lowlight in that area are dozens of university and company document classes derived from some old AMSLaTeX class in prehistoric times that redefined \endfigure in a way incompatible with quite a few packages. Among them preview.sty written by me.

After about 5 bug reports about 5 different classes, explaining what was wrong and why it broke quite a few packages, not just preview-latex, and how people should fix it and how they should complain to the people giving them the package... preview.sty just patches the problematic definitions if it has a reasonable guess that they are in place, and blows out a stern and verbose warning explaining where to complain and why.

Of course, nobody ever does.

Don't educate people. Just don't trigger their problems. Of course, there are millions of ways of shooting oneself in the foot, but in this case the same foot has been hit several times already.

-- 
David Kastrup