Re: [gtk-osx-users] Error when compiling gobject-introspection on macOS 10.13

[John Ralls <jralls ceridwen us>]

> On Sep 16, 2017, at 1:04 PM, Jiří Techet <techet gmail com> wrote:
>
> Just check the backtrace from the first email - there's no C involved. The error message comes from
>
> /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/spawn.py
>
> Jiri
>
> On Sat, Sep 16, 2017 at 9:53 PM, John Ralls <jralls ceridwen us> wrote:
>
> > On Sep 16, 2017, at 12:44 PM, Jiří Techet <techet gmail com> wrote:
> >
> > Hi John,
> >
> > at least from the backtrace it doesn't seem to happen when linking libpython but rather when running 
> > preprocess() from
> >
> > https://docs.python.org/2/distutils/apiref.html
>
> Huh. That's odd, there's no reason that should care about deployment target. You're sure it's using 
> /usr/bin/python, not linking libpython and calling distutils.preprocess() from C?

Jiri,

Sorry for forgetting about this thread.

We're both wrong, of course. The preprocess function runs cpp, the C preprocessor, on the file. That does 
everything starting with # in the file: Composes the compilation unit with #include, selects code blocks in 
#if..#else...#endif, and runs all of the preprocessor macros including MAC_OS_X_MIN_SUPPORTED and 
MAC_OS_X_MAX_ALLOWED, hence the failure.

But looking through giscanner/ccompiler.py I see that it also has a compile function that does exactly what 
one would expect. That will also get tripped up by MAC_OS_X_MIN_VERSION/MAX_ALLOWED.

So either work up a generic patch for ccompiler.py that figures out if there's a mismatch between the 
MACOSX_DEPLOYMENT_TARGET set for building the library and the one used by python or just build python as part 
of bootstrapping your build environment.

Regards,
John Ralls