>I've had very similar trouble on a 486 machine and to a lesser extent
>on a SS1+ (perhaps I should cross-post this to port-sparc).

Interesting.  I have a sparc2 and an i486 both running 1.4 (from the 
distibution binaries), and on both sh often dumps core (bus error)
when running the last bit of my configs tool.  
There is nothing remotely tricky in that and the core files 
don't help much - I'll rebuild with -g and see.

Fwiw the same script has run on many *nix flavours including NetBSD 1.3
on the same pair of machines for years, so its something in 1.4, 
either sh or something worse.  Mind you I've not seen _any_ other 
problems with 1.4, and I've built a few kernels on each machine.

--sjg