Make the default of the PYTHON variable consistent

[tyilo]

in the mac and linux makefile.

[oleavr]

I don't think the -f option exists in the BSD readlink; did you check if this works on Mac?

[tyilo]

You're right. Is there even a reason that we need to resolve the symlink if PYTHON is a symlink?

[oleavr]

Ok. It's just to have the directories not clash inside build, so you can do "make" and later "make PYTHON=/foo" to build another python binding side-by-side.

[tyilo]

That explains why we need to get the path to the python binary, but not why we need to resolve the symlink.

[oleavr]

Because which python might be a symlink, and we use its basename to name the directory. Ideally we want it to end up as e.g. lib/python2.7, so you can do make PYTHON=/usr/local/bin/python3.4 later to have lib/python3.4 side-by-side.

[tyilo]

Say I have two versions of python 2.7.x installed, eg. OS X system one and another one from homebrew, would they be built side by side?
If yes, then we need to resolve the symlink.
If no, we just need to detect the python version, which we should do by running $(PYTHON) -c 'import sys; v = sys.version_info; print "{}.{}".format(v[0], v[1])'

[oleavr]

No, they'll still clash. This is however not a very important feature. I'd say just to proper detection like you mentioned, it's way better anyway.

[oleavr]

Sweet!