Ubuntu – Python corrupted: how to clean a failed install or reinstall a fresh instance

TL;DR:

The following fixed it for me:

sudo chmod -r 755 /usr/local/lib/python2.7/dist-packages/

and

sudo reboot

My debugging path

I'm experiencing the same issues with ubuntuone and software-centre. These are the following steps I took to further debug this issue:

U1_DEBUG=True /usr/lib/ubuntu-sso-client/ubuntu-sso-login

which led to the following output:

...
Traceback (most recent call last):
  File "/usr/lib/ubuntu-sso-client/ubuntu-sso-login", line 67, in <module>
    from ubuntu_sso.main import main
  File "/usr/lib/python2.7/dist-packages/ubuntu-sso-client/ubuntu_sso/main/__init__.py", line 39, in <module>
    from twisted.internet import defer
  File "/usr/lib/python2.7/dist-packages/twisted/__init__.py", line 53, in <module>
    _checkRequirements()
  File "/usr/lib/python2.7/dist-packages/twisted/__init__.py", line 40, in _checkRequirements
    raise ImportError(required + ".")
ImportError: Twisted requires zope.interface 3.6.0 or later.

I then installed the zope.interface :

sudo easy_install zope.interface

I've tried it out in the python interpreter:

>>> import zope.interface

and got a few "Permission denied" errors on the Python packages:

IOError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/dist-packages/httplib2-0.8-py2.7.egg/EGG-INFO/top_level.txt'IOError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/dist-packages/httplib2-0.8-py2.7.egg/EGG-INFO/top_level.txt'

after which I decided to change access permissions to the file:

sudo chmod -r 755 /usr/local/lib/python2.7/dist-packages/

which resulted in the GUI of Ubuntu One to pop and attempt to sync. Only to receive a dBus exception afterwards in a pop-up window. At least the GUI started working...

For Software Centre, I ran the following command in the terminal:

software-center --debug

got a few more of the same dBus exceptions and googling the issue I found out that a restart suffice it for the exceptions to go away which are triggered due to a timeout.

I had the same issue, Ubuntu 16.04, 64-bit and a reinstall of all the supporting packages:

sudo aptitude reinstall apt apt-utils aptdaemon aptdaemon-data update-manager update-manager-core dbus

solved the issue. For note, a temporary workaround was to run sudo aptd in another terminal before running update-manager, and then update-manager was able to connect to aptd over dbus.

Unfortunately, I can't determine which package was the precise fix now that my issue is solved but if you try reinstalling each one-by-one, you can report back. A number of packages are/were broken on my system by a failed install resulting in odd issues like this one because of missing files, permissions and scripts; reinstalling packages is fixing these problems.