摘要：
错误：正在读取包列表…DoneE:ProblemexecutingsscriptsAPT:：Update:：Post Invoke Success“如果/usr/bin/test w/var/cache/app-info a-e/usr/bin/appstreamcli；thenapstreamclirefresh>；/dev/null；fi'E：子流程
错误：
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
在运行sudo apt-get update时出现如上信息，解决方法如下：
sudo pkill -KILL appstreamcli
wget -P /tmp https://launchpad.net/ubuntu/+archive/primary/+files/appstream_0.9.4-1ubuntu1_amd64.deb https://launchpad.net/ubuntu/+archive/primary/+files/libappstream3_0.9.4-1ubuntu1_amd64.deb
sudo dpkg -i /tmp/appstream_0.9.4-1ubuntu1_amd64.deb /tmp/libappstream3_0.9.4-1ubuntu1_amd64.deb
执行完上述命令之后再次运行sudo apt-get update就不会再出现上面的错误。
参考：
https://askubuntu.com/questions/774986/appstreamcli-hanging-with-100-cpu-usage-during-update