Comment 38 for bug 1752150

Paulo, I'm guessing you don't see the ngspice package because you haven't synchronized pacman

Try running:

pacman -Syu

from a msys2 shell. You'll need to repeat this process if it updates some core components, so I recommend running it, closing the shell once it is done, and then repeating to be sure. After that, you should be able to install ngspice package.

I understand your frustration in getting KiCad building on Windows. It is hard to maintain up-to-date build instructions for all platforms when we don't really have that many developers (and many of them only use Linux or MacOS). It is time-consuming to "start from scratch" to make sure that things actually work from the ground up, so it doesn't happen as often as it would in a commercial setting with a dedicated software QA team. Please keep reporting issues with our documentation when you come across them and we'll try to keep up as dependencies change.