apt source:
deb http://mirrors.163.com/ubuntu/ xenial main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ xenial-security main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ xenial-updates main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ xenial-proposed main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ xenial-backports main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ xenial main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ xenial-security main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ xenial-updates main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ xenial-proposed main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ xenial-backports main restricted universe multiverse报错
E: Failed to fetch http://mirrors.163.com/ubuntu/dists/xenial/main/binary-arm64/Packages 404 Not Found [IP: 59.111.0.251 80]
E: Failed to fetch http://mirrors.163.com/ubuntu/dists/xenial-security/multiverse/binary-arm64/Packages 404 Not Found [IP: 59.111.0.251 80]
E: Failed to fetch http://mirrors.163.com/ubuntu/dists/xenial-updates/multiverse/binary-arm64/Packages 404 Not Found [IP: 59.111.0.251 80]
E: Failed to fetch http://mirrors.163.com/ubuntu/dists/xenial-proposed/main/binary-arm64/Packages 404 Not Found [IP: 59.111.0.251 80]
E: Failed to fetch http://mirrors.163.com/ubuntu/dists/xenial-backports/universe/binary-arm64/Packages 404 Not Found [IP: 59.111.0.251 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.调整
deb http://us.archive.ubuntu.com/ubuntu/ lucid main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ lucid main restricted报错
E: The repository 'http://us.archive.ubuntu.com/ubuntu lucid Release' does not have a Release file最终解决
https://askubuntu.com/questions/431375/list-of-available-ubuntu-packages-for-arm-processors
deb http://ports.ubuntu.com/ubuntu-ports/ bionic main restricted universe multiverse\n\
deb http://ports.ubuntu.com/ubuntu-ports/ bionic-security main restricted universe multiverse\n\
deb http://ports.ubuntu.com/ubuntu-ports/ bionic-updates main restricted universe multiverse\n\
deb http://ports.ubuntu.com/ubuntu-ports/ bionic-proposed main restricted universe multiverse\n\
deb http://ports.ubuntu.com/ubuntu-ports/ bionic-backports main restricted universe multiverse\n\
deb-src http://ports.ubuntu.com/ubuntu-ports/ bionic main restricted universe multiverse\n\
deb-src http://ports.ubuntu.com/ubuntu-ports/ bionic-security main restricted universe multiverse\n\
deb-src http://ports.ubuntu.com/ubuntu-ports/ bionic-updates main restricted universe multiverse\n\
deb-src http://ports.ubuntu.com/ubuntu-ports/ bionic-proposed main restricted universe multiverse\n\
deb-src http://ports.ubuntu.com/ubuntu-ports/ bionic-backports main restricted universe multiverse\n