Python discovery is sometimes wrong

[tdsmith]

The Python discovery logic in configure is a little surprising. If python-config exists, asking it for include paths with python-config --includes may be more robust than using find in the parent of the directory holding the Python binary to locate a Python.h.

Here is a report of a situation where, building the geos python extensions against OS X's system python, pypy's Python.h was discovered instead of Python's, which caused trouble: ​https://github.com/Homebrew/homebrew/issues/49725

Also, extension modules built on OS X generally should not explicitly provide -lpython to the linker and should use -undefined dynamic_lookup instead, so that it can be used with any compatible Python interpreter. I've written a blog post that describes this problem more extensively: ​http://blog.tim-smith.us/2015/09/python-extension-modules-os-x/

Thanks! Tim

[pramsey]

We seem to have evolved beyond this ticket by just not having our own python support anymore, it'll all delegated to pygeos and shapely projects.