On TX2, apt-get 'Unable to locate package nvidia-jetpack'

I have a TX2 with factory image on it, I tied to run the package install instructions for JetPack SDK

https://docs.nvidia.com/jetson/jetpack/install-jetpack/index.html

On my TX2 I ran the apt-get install command from section 1.3, but it says “unable to locate package nvidia-jetpack”

$ sudo apt-get install nvidia-jetpack                                                                            
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package nvidia-jetpack

Is there something I should be doing to point apt to an nvidia repository?

Or am I misunderstanding the instructions, and the "apt-get install nvidia-jetpack " is supposed to be done
on a PC host running the NVIDIA development tool kit, that I then will use to build and then flash an OS filesystem image to the TX2 system?

What is your currently installed release? See:

head -n 1 /etc/nv_tegra_release

The first release where an NVIDIA repo is used is R32.3.1. If this is older, then you’d need to use JetPack/SDK Manager 4.3 to have this set up (but then the apt commands should work). For the most recent JetPack (currently 4.3) see (you might need to go there, log in, then go there again if redirect isn’t working):
https://developer.nvidia.com/embedded/jetpack

Thanks, so the process is to flash a new JetPack 4.3 image onto the TX2 using SDK Manager from a host computer?

Does flashing a new release erase everything (i.e., user home directories) that’s in the current filesystem on the TX2, or just change the OS-specific files?

This is correct, flash from host, and this will erase the content of the existing installation. You’d have to perform backup of anything important. In some cases people will clone the entire rootfs partition, or use more traditional tools such as rsync or simple file copy.

Great thanks!

This should work. Please try with linuxdev’s suggestion first.
If issue is still after re-flash, please let us know.