You might try installing on the T60 Thinkpad. Supports a maximum of 4GB of RAM.
(...)
Yes, I know, but I am interested in what happend between gnumach 2022.12.24 and 2022.04.10 that my computer couln't start.
Unfortunatelly I'm not good enoguht to investigated it.
P.S. OpenBSD should probably work on a computer with 1/2 a GiB of RAM. Give that a shot.
Debian/Linux 11 is working too, but I'm interested in Debian/Hurd :-)