How exactly does the language-changing mechanism work in the game or "Why language doesn't change"?

[TheLightTwist]

I had run into an interesting problem before, and it looks like I ran into it again this time, but I now have Arch instead of Windows.
But for some reason I'm sure it's not the game's problem, but mine, that I set one of the system variables related to localization incorrectly somewhere.
The problem is the same as in that issue, but on a different system
#45238

[TheLightTwist]

Hmm, that's the second time today that I've run into problems through my own fault and solved them myself. Oh, that Linux.
Anyway, the version in the AUR doesn't have a lang folder, just MOTD and some other lines.
Downloading the build from the website solves the problem.
So I went to build my own package