Thanks, and I take your point and I acknowledge that I probably made a typo the first time I ran 'python3.7 nanovna-saver.py' to run nanovna-saver. I had evidently missed the final 'r' off, perhaps while copy and pasting it. However, the 'bdist_wheel' thing happens either way. As mentioned, I have this logged on their Gitub and mihtjel has kindly said that he will look into it, although he also confirmed that no functionality would be missing.
Regading the dependencies, with the exception of listing them, there are no instructions given for the download/install of them, including this one. This is not unusual as it is usually left to the user to figure that out. PIP seems to be being used only to install the nanovna-saver package. On Debian and derivatives (Ubuntu/Mint) the way to install these dependencies would usually be e.g. "sudo apt install numpy", but that does not work as there is no such package. I also imagine that there is likely a difference between the package that I already had installed and initially tried to run against, namely 'python-numpy' and the one named 'python3-numpy'. They look like different versions of this python module and I now have both installed. However I agree, that this doesn't mean that there is a problem with numpy per se, only that the instruction, as stated in both the downloaded nanovna-saver README.md and on their Github is ambiguous and I just wanted to bring that to attention in case anyone else who has little Linux experience runs into the same problem.
I did a couple of tests by removing python3-numpy, and running nanovna-saver with python-numpy and it seemed to run OK. I then did the opposite and removed python-numpy and then re-installed python3-numpy. Nanovna-saver also seemed to run OK with this version, so perhaps the program does not seem to mind which version is installed, so long as at least one of them is. Python3-numpy would seem to be more consistent with the version of the other two python dependencies mentioned, i.e. python3-serial and python3-pyqt5 but I will wait to see what mihtjel advises.
