The dns related modules fails to load on OSX: cannot import name 'Opcode'

[nresare]

Version information

head from github, 6740c10

Steps to replicate

1. You need an OSX machine with a default case insensitive filesystem (something you get if you install a recent version without any special partitioning options)
2. Install a recent python (I use python3 from brew) and virtualenv.
3. Install the default deps from python3.txt and tests.txt with pip install -r
4. Run py.test tests/unit/test_plugins/test_dns_eval.py

Actual result

==================================== ERRORS ====================================
__________ ERROR collecting tests/unit/test_plugins/test_dns_eval.py ___________
tests/unit/test_plugins/test_dns_eval.py:3: in <module>
    import oa.dns_interface
oa/dns_interface.py:9: in <module>
    import dns
../../.virtualenvs/oa-2.7/lib/python3.6/site-packages/dns/__init__.py:24: in <module>
    from . import Opcode
E   ImportError: cannot import name 'Opcode'

Expected result

Test success

Other notes

The reason for this is that py3dns and dnspython, being installed in modules dns and DNS respectively end up in the same directory because of the case insensitive nature of the OSX filesystem and end up clobbering each other.

Since dnspython seems like the more widely used and feature complete library I think that the non-hacky way forward here is to convince pyspf upstream to release a version that uses dnspython instead of py3dns and work around the problem. Fortunately it seems like the individual that uploaded the latest version of pyspf has some stale code in his github repo that makes pyspf dns library agnostic.

[jayvdb]

nresare/dnsplug#2 could be the solution, that you already prepared earlier .. ;-)

[jayvdb]

rthalley/dnspython#303 for some responses from the maintainers about the conflict.