Several years ago a patch was applied to set the default binding of the pydoc server to "localhost" instead of "0.0.0.0". It appears that the issue was reintroduced in a5a3ae9be1fb.

See previous issue: http://bugs.python.org/issue672656

$ ./python -m pydoc -b
Server ready at http://localhost:35593/
Server commands: [b]rowser, [q]uit
server> 

---

$ netstat -lnp | grep python
tcp        0      0 0.0.0.0:35593           0.0.0.0:*               LISTEN      2780/python


As a sidenote, I'm not sure why the localhost lookup breaks the test case on my linux machine, but it does.