Comment 2 for bug 1805192

Thank you for reporting this bug and helping to improve Ubuntu.

The error in your log is:

Processing triggers for update-notifier-common (0.154.1ubuntu3) ...
/var/lib/dpkg/info/update-notifier-common.postinst: 16: /var/lib/dpkg/info/update-notifier-common.postinst: /usr/lib/update-notifier/package-data-downloader: not found
dpkg: error processing package update-notifier-common (--purge):
 le sous-processus script post-installation installé a retourné une erreur de sortie d'état 127
[...]

This is unusual; if the package is being purged, then there is no reason that the trigger for the package should be called. This looks to me like it may be some sort of bug in dpkg in terms of handling the state of a package in the process of being removed. Reassigning this bug to dpkg.

However, I also notice from your logs that the reason that this package is being purged is that you are trying to run 'apt purge python2.7-minimal' on an Ubuntu 14.04 system. As the logs show, this tries to remove a large number of packages which as of Ubuntu 14.04 still required python2. It removes the ubuntu-desktop metapackage, which means future upgrades of your system cannot be handled as expected.

If you want to remove python2.7 from your system, I would recommend you first upgrade to the current supported LTS release (Ubuntu 18.04 LTS), which no longer pulls python2.7 into the Ubuntu Desktop.