How to fix “arm64 Packages 404 Not Found [IP: 91.189.91.23 80]” on host PC after JetPack installation

This problem does not always occur but it does once in awhile. And after many times flashing Jetpack in the past, I faced this problem eventually after flashing Jetpack 4.1.1 on Jetson Xavier. Particularly, you run into these update error when you try to sudo apt-get update

So the way to fix this is to require modification on the /etc/apt/sources.list file. You need to add [arch=amd64,i386] in every line starting with deb in the file like this:

For Ubuntu beginner:

• How to edit this file, you need superuser privilege sudo gedit /etc/apt/sources.list (I use gedit editor, but you can replace it with other editor of your choice such as nano, vim, etc…).
• After editing, save the file and then sudo apt-get update again, the problem should go away.

References:

https://devtalk.nvidia.com/default/topic/1004601/jetson-tx2/after-installing-jetpack3-0-host-computer-is-not-able-to-apt-get-update/
https://docs.nvidia.com/cuda/cuda-installation-guide-linux/#advanced-setup (in the Advance-setup section with mention “Modify Ubuntu’s apt package manager to query specific architectures for specific repositories. This is useful when a foreign architecture has been added, causing “404 Not Found” errors to appear when the repository meta-data is updated.)