[Beowulf] backtraces

[Mark Hahn]

I had a user grumble about how it was not trivial to get 
a basic backtrace on our clusters.  his jobs tend to be 32-128p,
and run for a week, so it's not ideal to run them under the debugger.

turns out to be fairly simple to produce a backtrace.so which can
be LD_PRELOAD'ed - it contains a constructor which registers a 
signal handler, which obtains the backtrace and translates and 
prints the corresponding file:func:line.

does this sound like something of interest to other HPC sites?

regards, mark hahn.