salt: ext/ipaddress.py broken on 2019.2 when using python 3

Description of Issue/Question

Salt is choking when one of my ext_pillars imports the ipaddress module.

Here’s an example (obviously not the real thing, but should serve the purpose of demonstration):

#!/usr/bin/env python3.4
import ipaddress

# fdb3:de94:8a2b::1
i = b'\xfd\xb3\xde\x94\x8a+\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01'
ip = ipaddress.ip_address(i)
ip = str(ip)
print(ip)

When executed directly with python 3.4 (see below for full environment), it behaves as expected, and prints fdb3:de94:8a2b::1.

However, it seems salt is modifying the python path, and instead of using the system ipaddress module, it’s using ext/ipaddress.py (which is shitbroken):

Traceback (most recent call last):
  File "./poc.py", line 3, in <module>
    import ipaddress
  File "/usr/lib/python3.4/site-packages/salt/ext/ipaddress.py", line 15, in <module>
    from itertools import imap as map
ImportError: cannot import name 'imap'

Which of course makes sense, because imap doesn’t exist in python 3 itertools. (I initially noticed this when the ext_pillar refused to render a “packed” IPv6 address with 'hex' is not a text encoding; use codecs.encode() to handle arbitrary codecs - which is also true, because .encode('hex') does not work in python 3. Reference: line 50 and line 56 of ext/ipaddress.py.)

I’d recommend doing a conditional prepending of the python path for ext_pillars.

Stupid-quick simple demo:

import sys

# https://docs.python.org/3/library/sys.html#sys.hexversion
tgtver = 0x300000f0  # would match 3.0.0; 0x30409f0 would match v 3.4.9, etc.
pyver = sys.hexversion

if pyver < tgtver:
    sys.path.insert(1, 'ext/')  # or whatever

This unfortunately is a blocker for me, as I now need to rollback (I’m using the RedHat/CentOS 7 PY3 Saltstack repo) and it renders any minion (and master) that updates to 2019.2.0 unusable.

Setup

N/A

Steps to Reproduce Issue

See above

Versions Report

Salt Version: Salt: 2019.2.0

Dependency Versions: cffi: 1.11.5 cherrypy: unknown dateutil: Not Installed docker-py: Not Installed gitdb: Not Installed gitpython: Not Installed ioflo: Not Installed Jinja2: 2.8 libgit2: 0.26.8 libnacl: Not Installed M2Crypto: Not Installed Mako: Not Installed msgpack-pure: Not Installed msgpack-python: 0.5.6 mysql-python: Not Installed pycparser: 2.17 pycrypto: 2.6.1 pycryptodome: Not Installed pygit2: 0.26.4 Python: 3.4.9 (default, Feb 5 2019, 14:36:09) python-gnupg: Not Installed PyYAML: 3.11 PyZMQ: 15.3.0 RAET: Not Installed smmap: Not Installed timelib: Not Installed Tornado: 4.4.2 ZMQ: 4.1.4

System Versions: dist: centos 7.6.1810 Core locale: UTF-8 machine: x86_64 release: 3.10.0-957.5.1.el7.x86_64 system: Linux version: CentOS Linux 7.6.1810 Core

(same for minion and master)