Ubuntu 16.04でapt updateできない不具合に対処するスクリプト https://kledgeb.blogspot.com/2016/05/ubuntu-1604-57.html

fix_appstream_on_ubuntu16.04.sh

#!/usr/bin/env bash
set -eu
[ $(pgrep appstreamcli | wc -l) -gt 0  ] && { echo 'kill process "appstreamcli"'; exit 1; }
mkdir -p /tmp/asfix && cd /tmp/asfix
wget https://launchpad.net/ubuntu/+archive/primary/+files/appstream_0.9.4-1ubuntu1_amd64.deb
wget https://launchpad.net/ubuntu/+archive/primary/+files/libappstream3_0.9.4-1ubuntu1_amd64.deb
sudo dpkg -i *.deb
echo 'Probably fixed. Run "apt update".'

Usage

run the followings on your terminal:

$ curl -SsfL git.io/fix-appstream-ubuntu16.04 | sh