apt-get, apt and aptitude work all just fine and produce no errors nor warnings.
update-notifier/apt-check is, indeed, responsible for the error message. gioele:~$ /usr/lib/update-notifier/apt-check Error in sitecustomize; set PYTHONVERBOSE for traceback: AttributeError: module 'sys' has no attribute 'setdefaultencoding' 0;0gioele:~$ echo $? 0 Please note the missing newline between the end of the output of apt- check and the prompt. gioele:~$ which python /usr/bin/python gioele:~$ readlink -f /usr/bin/python /usr/bin/python2.7 Thank you Sebastien for the triaging. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-software in Ubuntu. https://bugs.launchpad.net/bugs/1702467 Title: software update indicator crashes and displays wrong error message Status in gnome-software package in Ubuntu: Incomplete Bug description: On a fresh Ubuntu 16.04.2 LTS install, the software update indicator indicator crashes (probably during startup) and reports the a mangled error. It states > The error message was 'ror in sitecustomize; set PYTHONVERBOSE > for traceback: AttributeError: module 'sys' has no attribute > 'setdefaultencoding' 0;0'. Please note the "ror" instead of "Error" at the beginning of the reported error message. The attached screenshot shows this error. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: gnome-software 3.20.1+git20170524.0.ea2fe2b0-0ubuntu0.16.04.1 ProcVersionSignature: Ubuntu 4.8.0-56.61~16.04.1-generic 4.8.17 Uname: Linux 4.8.0-56-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.6 Architecture: amd64 CurrentDesktop: Unity Date: Wed Jul 5 13:46:26 2017 ExecutablePath: /usr/bin/gnome-software InstallationDate: Installed on 2017-06-24 (10 days ago) InstallationMedia: Ubuntu 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170215.2) SourcePackage: gnome-software UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-software/+bug/1702467/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp