Package install error in python3-newt on trusty

[Casey Marshall]

Packages were up to date at time of writing (apt-get update && apt-get dist-upgrade after xubuntu 14.04 install). Then I installed byobu, which pulled in python3-newt as a dependency, and I got this package install error:

Setting up python3-newt (0.52.15-2ubuntu4) ...
Exception ignored in: <bound method Popen.__del__ of <subprocess.Popen object at 0x7f598c2d52b0>>
Traceback (most recent call last):
  File "/usr/lib/python3.4/subprocess.py", line 897, in __del__
TypeError: 'NoneType' object is not callable
Exception ignored in: <bound method Popen.__del__ of <subprocess.Popen object at 0x7f598c2d5320>>
Traceback (most recent call last):
  File "/usr/lib/python3.4/subprocess.py", line 897, in __del__
TypeError: 'NoneType' object is not callable