SS4 just freezes NetBSD 10

Hi,

I tried to investigate the issue even more with my SparcStation 4 which 
initially worked fine with NetBSD 10

Test is always the same: try to compile packages. Due to the small 
internal HD, sources and binary destinations are over NFS. Local is OS, 
tools, work directory and swap. I attached keyboard&monitor

Some packages compiled, but now I have pcre consistently failing and 
locking up the computer. What I wonder is that there is absolutely no 
print out on the screen. Nor kernel message nor nothing. Lock up means 
also no input from local console where I precedently logged in..

I kept a telnet open with top and the last thing I see is this:

load averages:  0.99,  0.95,  0.92;               up 
0+05:18:25                                              17:47:51
33 processes: 1 runnable, 31 sleeping, 1 on CPU
CPU states: 89.5% user,  0.0% nice,  2.4% system,  0.8% interrupt, 7.3% idle
Memory: 60M Act, 10M Inact, 9120K Exec, 5500K File, 2212K Free
Swap: 512M Total, 153M Used, 360M Free / Pools: 15M Used / Network:

   PID USERNAME PRI NICE   SIZE   RES STATE       TIME   WCPU    CPU COMMAND
13657 root      26    0   160M   58M RUN        23:10 66.11% 66.11% cc1
11937 multix    43    0  7472K 1676K CPU         0:18  0.73%  0.73% top


so busy, but it still had a little memory and swap left.

If I power-cycle, it just boots fine...

My obvious suspect is NetBSD 10, since that is what "changed" but I find 
such a hard lock-up strange.

The machine used to be stable on 9.3 NetBSD.. but of course this was 
months ago and with old hardware you never know.

Riccardo