However it takes 24 minutes even to build ancient small emacs-18.59. simh emulating microvax3900 on my i5-4570 NetBSD/amd64 took ~70 hours to build perl 5.38.2 (from pkgsrc-2023Q4) so it won't finish in 6 hour github CI limit.
I suppose because additional cores can't be thrown at simh, this is a difficult limit.
What do others do when something comes close to that limit? Do they just add cores and increase -j?
John