[cairo] Making configure error message more clear

[Arjen Nienhuis]

On Sat, Apr 3, 2010 at 2:25 PM, Owen Taylor <otaylor at redhat.com> wrote:
> On Thu, 2010-03-25 at 17:04 -0400, Behdad Esfahbod wrote:
>> On 03/22/2010 02:10 PM, Carl Worth wrote:
>> > On Thu, 18 Mar 2010 21:15:33 +0100, Arjen Nienhuis <a.g.nienhuis at gmail.com> wrote:
>> >>> Below is an exchange I recently had with a new user trying to use cairo
>> >>> who got this error and followed its advice, (browsed to the URL, found
>> >>> pixman, downloaded it, installed it to the default /usr/local/). But the
>> >>> user still got the same message, and never knew to adjust the
>> >>> PKG_CONFIG_PATH environment variable.
>> >>
>> >> Why isn't PKG_CONFIG_PATH set to $PREFIX/lib/pkgconfig by default?
>> >
>> > I've often wondered why pkg-config doesn't do that by default.
>> >
>> > But I suppose that we could just have cairo's configure script set that
>> > environment variable that way if it's not already set. That would be a
>> > nice solution for this problem.
>>
>> Interesting.  Why pkg-config doesn't do it is not hard to see.  Why shouldn't
>> it provide a macro to do that, good q.  I'll fix it in cairo and propose other
>> packages doing the same.
>
> It's always been completely clear that configure --prefix=<X> is about
> where the package is *installed*, not where the build process looks for
> things.
>
> Now, there's maybe no reason that the configure process couldn't guess
> that where you are installing is where you want to find things too, but
> I'm sort of skeptical that it's a good idea for a few packages to start
> doing that in one aspect PKG_CONFIG_PATH (but not other aspects like
> include and library paths.)
>

Disclaimer: I don't really know what I'm talking about.

I thought that's what pkgconfig is for: finding the include and
library paths. What else is it for?

Met vriendelijke groet,

Arjen Nienhuis