I have the same problem, and it happens with both apt-get and synaptic when I try to update the list of packages.
It has nothing to do with installing without an internet connection, as for me this just started happening tonight (it worked fine before). A "workaround" is to remove the appstream package, which also removes the GNOME/Ubuntu Software package (the GUI software installer), which is fine for me (I never use those anyway), but probably not for "regular" users... -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to appstream in Ubuntu. https://bugs.launchpad.net/bugs/1583845 Title: Can't "apt-get update" - appstreamcli stuck at 100% Processor Utilization Status in appstream package in Ubuntu: Confirmed Bug description: I did a fresh install of Ubuntu 16.04 without being connected to the internet because when connected to the internet the install would lock up at the point that ubuntu was "Retrieving 56 of 56". Installation (without internet) was successful, then I connected to the internet and tried to update: The update-process seemed to be stuck, so I discovered that the command appstreamcli was at 100% processor utilization indefinitely. When I kill that process the update fails. This is clearly a bug, but hopefully someone can suggest a work-around until it is fixed. user@pc:~$ sudo apt-get update Get:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB] Hit:2 http://us.archive.ubuntu.com/ubuntu xenial InRelease Get:3 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease [94.5 kB] Get:4 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease [92.2 kB] Fetched 281 kB in 0s (387 kB/s) Terminated Reading package lists... Done E: Problem executing scripts APT::Update::Post-Invoke-Success 'if /usr/bin/test -w /var/cache/app-info -a -e /usr/bin/appstreamcli; then appstreamcli refresh > /dev/null; fi' E: Sub-process returned an error code ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: appstream 0.9.4-1 ProcVersionSignature: Ubuntu 4.4.0-22.40-generic 4.4.8 Uname: Linux 4.4.0-22-generic x86_64 ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 Date: Thu May 19 19:08:30 2016 InstallationDate: Installed on 2016-05-19 (0 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1) ProcEnviron: LANGUAGE=en_US TERM=xterm-256color PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: appstream UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/appstream/+bug/1583845/+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
