Re: [RFC] getting rid of the config.guess/sub problem when bootstrapping new ports/systems

[Wookey]

+++ Eric Blake [2013-05-20 09:11 -0600]:
> On 05/20/2013 09:01 AM, Paul Wise wrote:
> > On Mon, 2013-05-20 at 08:37 -0600, Eric Blake wrote:
> > 
> >> I would MUCH rather see us honor a CONFIG_GUESS and CONFIG_SUB
> >> environment variable, rather than baking in a PATH search.  This topic
> >> has come up in the past, where I made the same request back then.
> > 
> > The patch does both and both are needed AFAICT.
> 
> I disagree.  Env-var override should be sufficient, without needing any
> PATH probing.

The problem with this in the context of distro buildds was explained
in this sub-part of the thread from Oct last year:
http://article.gmane.org/gmane.comp.sysutils.autoconf.general/14756

ENV VARS are carefully filtered out of buildd environments in order to
get clean builds. We really want a mechanism where the distro default
build just looks in the right (system) place, unless you ask for
something different.

Now it probably is possible to get this ENV VAR set in buildd
environments, but what if the cmake, maven, ant, scons and $everybody
else also insist on the same mechanism for default builds to work
properly? That's a lot of ENV VARS - it doesn't scale well. And if
someone does a local build outside the buildd environment now they
have to remember to set these variables too, otherwise suddenly stuff
that built on the buildds doesn't build for them.

ENV VARS are very useful for all sorts of things, but they are
problematic for distro build defaults, so there is a good reason for
the path walk.

Now we could patch autoconf in Debian (and other distros patch it too)
to deal with this, but the whole point of this excercise is to fix this
upstream so that over time the problem will just fade into history. 

Wookey
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