> trap: textfault at 402068f8!! sending SIGILL due to trap 16: illegal instructionkdb breakpoint at 111469c
> Stopped in pid 512 (make) at    cpu_Debugger+0x4:       nop
> db> c

This seems to be related to process exit; i.e. a long running process never
is affected, but subshells terminating or childs of make exiting seem to
cause it. On the other hand this may be coincidential and this is some random
UBC/VM pagefault error; I've seen ld complain about bad libraries, and rerunning
the command worked - but, of course, this may be unrelated.

Lossage seems to cumulate - i.e. it's stable for some time, but after a few
faults it starts faulting all over the place.

db> mach tf
Trapframe 0x1431b08:    tstate: 4482000601      pc: 11146a0     npc: 11146a4
y: fffffff8     pil: 0  oldpil: 0       fault: 4482000601       kstack: 0       t
t: 101  Globals:
0000000000000000 0000000000000000 0000000001431800 0000000000000032
0000000000000000 0000000000000000 0000000000000000 0000000000000000
outs:
000000000112c7f0 0000000000101928 0000000000000010 000000000112c670
0000000000000400 0000000000000006 00000000059934e1 0000000001111b4c
locals:
0000000040205800 000000000593ce20 0000000000000007 0000000000000000
0000000000000000 0000000000000000 0000000000000000 0000000000000000
ins:
0000000000000010 0000000044820002 0000000000101928 0000000005993ed0
0000000000000000 0000000000000000 0000000005993621 0000000001008fb8


Martin