Contacted Carlos about the bug. He just pushed out a fix.

File "/usr/bin/dnsrecon", line 1640, in <module>
main()
File "/usr/bin/dnsrecon", line 1496, in main
spf_enum, do_whois, zonewalk)
File "/usr/bin/dnsrecon", line 953, in general_enum
recursive = check_recursive(ns_rcrd[2])
File "/usr/bin/dnsrecon", line 883, in check_recursive
response = dns.query.udp(query, ns_server)
File "/usr/lib/python2.7/dist-packages/dns/query.py", line 217, in udp
_wait_for_readable(s, expiration)
File "/usr/lib/python2.7/dist-packages/dns/query.py", line 140, in _wait_for_readable
_wait_for(s, True, False, True, expiration)
File "/usr/lib/python2.7/dist-packages/dns/query.py", line 116, in _wait_for
if not _polling_backend(fd, readable, writable, error, timeout):
File "/usr/lib/python2.7/dist-packages/dns/query.py", line 74, in _poll_for
event_list = pollable.poll()