native install instructions for Linux installs old version, doesn't upgrade, gives errors

[PatrickTague]

In following the instructions to native install newt on Ubuntu, following the instructions results in an install of newt version 1.7.0, which is out of date. In creating a test project and running newt upgrade, newt then complains that the installed newt version doesn't match the project repo that was downloaded, and fails. The install instructions also seem to suggest that running newt upgrade would upgrade the newt tool itself, but that doesn't seem to happen, so this seems to hit a wall.

Can someone quickly look into those install instructions and see if there is an error somewhere, or is there some other issue with Linux installation?

I'm attempting to install on a fresh Ubuntu 20.04 VM, following all of the instructions line by line, including adding i386 compilers and such.