It looks like my issue is probably unrelated, though it might cast some doubt on reliability of the node packages from various sources.
I'd been using Node installed as a Snap (which is actually an official release from the NodeJS foundation), and basically it just doesn't work in there. I can't figure it out yet, but frankly it's not the first time I've had extremely "minor" but crippling differences with the Snap package vs the other distributions of Node.
It worked absolutely fine for me when I'd installed Node from NodeSource · GitHub. I used to also just download the tarball release from the NodeJS site directly in the past.
It makes me wonder if there also be some subtle differences in the Arch Node package that just makes it different to other releases, for the purposes of the AUR build script, maybe downloading Node specifically from Download | Node.js - building with it, and discarding it after might produce different results.
(OFC I don't know AUR packaging guidelines so maybe they'd disapprove this)
