Mac OS X and pkg-config

[Stephan Bergmann]

On 06/10/2015 03:35 PM, Khaled Hosny wrote:
>> but since we already have PATH in config_host.mk it would perhaps be
>> possible to detect which directory the pkg-config is found in and
>> automatically filter that out of $PATH (unless it's something that
>> cannot be removed like /usr/bin).  would that be an improvement for you,
>> and/or would anybody object to that?

> I think setting PKG_CONFIG_* environment variables to empty values will
> make pkg-config not find any installed libraries, so if we can do that
> for LibreOffice build shell (or whatever it is called) on Mac OS X
> (either by default or only when pkg-config is found) it should make its
> presence an non concern for LibreOffice build.

I don't like any of that tweaking of env vars in the build system.  It 
makes matters more opaque instead of more transparent.

And while presence of pkg-config on the PATH might be a good heuristic 
to detect that the environment has been contaminated by MacPorts or 
their like, is polluting PATH the only thing those do (and which we 
would thus need to counter), or are they also polluting in other ways 
that subtly influence the build (and then cause headaches)?