It occurred to me that Geert Hendrickx wrote in gmane.os.netbsd.general:
> About the swap thing: my workstation has 1 Gb of RAM, so I didn't create a
> swap partition.

Why not? Swap is a useful thing to have, it might even make your system
faster. Furthermore, if you're into kernel development, you really need
at least the amount of physical memory, preferably more, so the system can
make a dump.

> After your comments I think it would be better to convert my 1Gb /tmp
> partition to a swap partition and use an mfs /tmp, is that all
> right?  

Well, it's worth a try. You can always revert back.