Jun 032016

Upgraded Ansible to version 2.1 on OS X El Capitan. First run, I get this error:
AttributeError: 'EntryPoint' object has no attribute 'resolve'

Googling for it, it seems like the cause is setuptools (!?) version that is too old. I did install Ansible by running pip2 install --upgrade --user ansible, which installed it in my home directory and also upgraded the setuptools package in my home directory, but that’s not the version that Python is picking up.

I’m using system’s Python 2.7, I didn’t install another one. And the system Python is looking for modules using a path that starts with /System/Library/Frameworks/Python.framework/Versions/2.7, so it’s going to pick up the system setuptools instead of the one in my home directory. This package can’t be upgraded because it’s protected by SIP and disabling that and updating the package might cause the system to misbehave.

One solution is to export PYTHONPATH in my environment. Problem is, I’m using both Python2 and Python3 and that variable applies to both. Setting PYTHONPATH to point to Python2’s modules would likely cause a bigger mess.

Better solution:
Create a file under the site-packages directory in my home folder ($HOME/Library/Python/2.7/lib/python/site-packages) that has a .pth extension. It’s going to be picked up before anything else runs and lines starting with import are going to be executed. This file will contain code that will insert our directory before everything else in sys.path, so it will be searched first:
import sys; sys.path = ["/Users/USERNAME/Library/Python/2.7/lib/python/site-packages"] + sys.path

Here’s a one-liner that will create the file: