config.guess invoking cc

[Karl Berry]

Ben, Jan, et al.,

Sorry; this Mac thing has once again devolved into meandering messages
(as Mac things always seem to do) with no immediate relevance to
config.guess.  I did my best to avoid this outcome when I asked for the
submissions, but obviously did not succeed.

Anyway, can you please consider Adam's original mail, which is
apparently the only comprehensible issue:

> invoking cc on Mac OS X 10.9 causes a graphical alert to be displayed,
> which tells the user to install Xcode (dev tools). This is unexpected ...

That is, as I understand it, invoking cc *at all* (namely in the dummy
compilation) on MacOSX puts up a *graphical* alert box, due to Apple's
infinite, um, wisdom.  Thus, the only workaround is not to do
  eval $set_cc_for_build

As I understand it again, it is a fact that all versions of Darwin later
than X are on 64-bit hardware.  Therefore, as far as I can see, it is
not in principle necessary to run the compiler to determine it.  And
this would be good, because config.guess is used in plenty of situations
that don't otherwise require a C compiler to be installed.

So ... if you'd accept a patch to avoid $set_cc_for_build on new-enough
Darwin, I can ask to determine what X is.

Thanks,
Karl