Hi, I was unable to reproduce in a lxd container of 16.04:
root@xenial:~# sudo apt install python3-six Reading package lists... Done Building dependency tree Reading state information... Done The following NEW packages will be installed: python3-six 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. Need to get 11.0 kB of archives. After this operation, 54.3 kB of additional disk space will be used. Get:1 http://archive.ubuntu.com/ubuntu xenial/main amd64 python3-six all 1.10.0-3 [11.0 kB] Fetched 11.0 kB in 0s (37.5 kB/s) Selecting previously unselected package python3-six. (Reading database ... 13842 files and directories currently installed.) Preparing to unpack .../python3-six_1.10.0-3_all.deb ... Unpacking python3-six (1.10.0-3) ... Setting up python3-six (1.10.0-3) ... root@xenial:~# If you have steps to reproduce that be very helpful, as out of the box this appears to work. I would also suggest updating your other packages to make sure things are not conflicting. ** Changed in: six (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to six in Ubuntu. https://bugs.launchpad.net/bugs/1578588 Title: package python3-six 1.10.0-3 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1 Status in six package in Ubuntu: Incomplete Bug description: package python3-six 1.10.0-3 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1 during upgrade to 16 ProblemType: Package DistroRelease: Ubuntu 16.04 Package: python3-six 1.10.0-3 ProcVersionSignature: Ubuntu 4.2.0-35.40-generic 4.2.8-ckt5 Uname: Linux 4.2.0-35-generic i686 ApportVersion: 2.20.1-0ubuntu2 Architecture: i386 Date: Thu May 5 11:18:04 2016 Dependencies: ErrorMessage: subprocess installed post-installation script returned error exit status 1 InstallationDate: Installed on 2016-03-20 (46 days ago) InstallationMedia: Xubuntu 15.04 "Vivid Vervet" - Release i386 (20150422.1) PackageArchitecture: all RelatedPackageVersions: dpkg 1.18.4ubuntu1 apt 1.2.10ubuntu1 SourcePackage: six Title: package python3-six 1.10.0-3 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1 UpgradeStatus: Upgraded to xenial on 2016-05-05 (0 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/six/+bug/1578588/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp