Error when running apt-get update

⇐ Known problems

• error when running apt-get update:

        error:  Traceback (most recent call last):
             File "/usr/lib/python3.5/weakref.py", line 117, in remove

• workaround

This seems to be fixable.

In short open /usr/lib/python3.5/weakref.py

and change line 109 to:

   def remove(wr, selfref=ref(self), _atomic_removal=_remove_dead_weakref):

And line 117 to:

   _atomic_removal(d, wr.key)

Note you need to do this with spaces, not tabs as this will cause other errors.