gobject-introspection: tweak scanner patch

[michaelld]

Now handles build-provided library paths more robustly, removing those that are already found via PKGCONFIG and are thus clearly "system" paths -- for MacPorts the most critical is -L${MACPORTS_PREFIX}/lib ...

Ref: https://trac.macports.org/ticket/61382

Tested on 10.15 and 11.0. Works for py38-gobject3, gexiv2, and libsoup.

[macportsbot]

Notifying maintainers:
@dbevans for port gobject-introspection.

[macportsbot]

Travis Build #14983 Passed.

Lint results

--->  Verifying Portfile for gobject-introspection
--->  0 errors and 0 warnings found.

Port gobject-introspection success on xcode10.3. Log
Port gobject-introspection success on xcode9.4. Log
Port gobject-introspection success on xcode8.3. Log
Port gobject-introspection success on xcode7.3. Log

[dbevans]

OK, let me try this out. Hopefully it will fix the issues generated by the last commit 😉

[michaelld]

OK, let me try this out. Hopefully it will fix the issues generated by the last commit 😉

Please do & yes hopefully! I've had good success with this PR's changes on various macOS & the ports listed ... in my testing it's pretty robust, covering a lot more situations than the initial change. There is the likely chance of corner cases, of course ... but I don't think they'll be difficult to fix once we know them!

[dbevans]

Tested ok with babl and gegl. So far so good. Will run a more exhaustive test over night and report back tomorrow. Keep your fingers crossed.

[dbevans]

After testing a lot of GNOME ports that use gobject-introspection, I didn't find any specific problems although there may be some lurking somewhere. I didn't find any but then I didn't rebuild all ports that use gobject-introspection either.

In any case, I propose to go ahead and merge this and then commit a number of updates that depend on it (including poppler). If there's something that can go wrong, that should flush it out. Thanks for all your work on this and the preceding PRs.