HKUST replacement source
Scheme A: In the command line type sudo gedit /etc/apt/sources.list, comes to open the source file system.
Delete the files in the source, replace the HKUST Source:
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
Save the file and exit, execute sudo apt-get update to update.
Execute sudo apt-get upgrade to update the relevant tools, be sure to update, otherwise there will be problems toolset version does not match.
Option II:
Find software and updates directly in ubuntu, as follows;
Download the self, which is the source address changes to HKUST site, close, wait for the update to complete.