I wasted half a day trying to build it on Win. The Win version didn't take so long, but it just wouldn't compile for Switch. Oh man what didn't I try. Reinstalled msys, combed my PATH, edited files... Even tried WSL.
Saw your post and it inspired me to try it on Arch. Built flawlessly with no tinkering whatsoever.
No probs, glad it helped.
I used this to change the icon to the .png supplied with the source. Out of aspect, but better than the cat picture.
https://gbatemp.net/threads/nro-asset-editor.499003/