Description of problem:

The following code:

#!/usr/bin/python3
import sys
import dns.resolver;
try:
    print("AFSDB:")
    for AFSDB in dns.resolver.query(sys.argv[1], "AFSDB"):
        print("\t" + str(AFSDB.hostname))
except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer):
    print("Couldn't find any AFSDB records")

when pointed at a place that produces a response with no pertinent answers, eg:

    /data/afs/dnstest.py your-file-system.com

or:

    /data/afs/dnstest.py www.redhat.com

tries to generate a NoAnswer exception, but incurs a KeyError exception whilst trying to do so and then yet another KeyError exception whilst trying to handle that:

warthog>/data/afs/dnstest.py your-file-system.com
AFSDB:
Traceback (most recent call last):
  File "/usr/lib/python3.5/site-packages/dns/resolver.py", line 157, in __init__
    rdclass, rdtype)
  File "/usr/lib/python3.5/site-packages/dns/message.py", line 333, in find_rrset
    raise KeyError
KeyError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.5/site-packages/dns/resolver.py", line 167, in __init__
    dns.rdatatype.CNAME)
  File "/usr/lib/python3.5/site-packages/dns/message.py", line 333, in find_rrset
    raise KeyError
KeyError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/data/afs/dnstest.py", line 6, in <module>
    for AFSDB in dns.resolver.query(sys.argv[1], "AFSDB"):
  File "/usr/lib/python3.5/site-packages/dns/resolver.py", line 1025, in query
    raise_on_no_answer, source_port)
  File "/usr/lib/python3.5/site-packages/dns/resolver.py", line 956, in query
    raise_on_no_answer)
  File "/usr/lib/python3.5/site-packages/dns/resolver.py", line 176, in __init__
    raise NoAnswer(question=response.question)
  File "/usr/lib/python3.5/site-packages/dns/exception.py", line 47, in __init__
    self._check_kwargs(**kwargs)
  File "/usr/lib/python3.5/site-packages/dns/exception.py", line 69, in _check_kwargs
    self.supp_kwargs)
AssertionError: following set of keyword args is required: {'response'}


On the other hand, invoking it with somewhere that has an AFSDB record works fine:

warthog>/data/afs/dnstest.py grand.central.org
AFSDB:
        grand-old-opry.central.org.
        grand.mit.edu.

As does giving it an invalid name:

warthog>/data/afs/dnstest.py grand.central.orgg
AFSDB:
Couldn't find any AFSDB records


Version-Release number of selected component (if applicable):

python3-3.5.1-17.fc24.x86_64
python3-dns-1.12.0GITa4774ee-1.fc24.noarch