Re: *-config programs and multi-arch

[Miles Bader <miles@gnu.org>]

Simon McVittie <smcv@debian.org> writes:
> That's the missing piece of the puzzle: some sort of cross-toolchain
> package (which doesn't exist yet in Debian - but neither does a
> cross-gcc) should make the symlink
>
>     x86_64-w64-mingw32-pkg-config -> /usr/share/pkg-config-crosswrapper
>
> in your $PATH. For the moment, making that symlink is part of the
> process of installing a cross-toolchain manually.

Ok, but still, it should be more robust when things are not set up properly.

>> It seems to me that the right thing in this case (no host-prefix
>> tool is found) is simply to act as if pkg-config was not present at
>> all, instead of using the non-host-prefixed version.
>
> Well, it does give you a warning... perhaps the warning should
> default to being fatal, but it's basically the same situation as any
> other missing cross-tool (e.g. if you had a cross gcc but no cross
> ld). autoconf currently stumbles on regardless, in the hope that
> your non-cross (build-arch) tool

I dunno, pkg-config is different, I think -- unlike a missing compiler
or linker, a missing pkg-config often simply means "you can't use any
libraries for which pkg-config is required", and missing libraries
[etc] is an issue which configure scripts are often prepared.

So the "pkg-config missing" => "fatal error" decision is really
something that should be left left to the configure script, not embedded
in the pkg-config autoconf macros.

However, the current state, where it pretends pkg-config is present,
when it really isn't in a useful way, just fools the configure script
into doing the wrong thing.

[For very important libraries, I often write the library test twice,
once with pkg-config, and once using traditional autoconf methods to
handle the no-pkg-config case.]

AFAICT, the easiest way to handle all this is just to make a missing
cross-pkg-config look like a missing pkg-config to the configure
script.  Then whatever logic the script may have for detecting the
"not pkg-config at all" case, will do the right thing for the cross
case too.

Thanks,

-miles

-- 
The automobile has not merely taken over the street, it has dissolved the
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[James Marston Fitch, New York Times, 1 May 1960]