如果之前jetson nano的apt install正常，突然出现这个问题，那很可能是你用apt源服务器崩了，我用的是华为云源，出现了如题报错，改成了清华源，就没问题了，也可以改成中科大源。
保存备份：
sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak
sudo gedit /etc/apt/sources.list
‘清华源：’
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic main multiverse restricted universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-security main multiverse restricted universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-updates main multiverse restricted universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-backports main multiverse restricted universe
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic main multiverse restricted universe
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-security main multiverse restricted universe
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-updates main multiverse restricted universe
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-backports main multiverse restricted universe
中科大源：
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic main restricted
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-updates main restricted
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic universe
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-updates universe
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic multiverse
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-updates multiverse
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-backports main restricted universe multiverse
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-security main restricted
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-security universe
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-security multiverse
修改好之后需要刷新一下 ：
sudo apt-get update