100% CPU utilization during (run)

I've noticed that when I start a subprocess from scsh, using the (run
(...)) syntax, during the execution of the subprocess the CPU
utilization for the scshvm process shoots up to 100% (as shown by the
"top" utility).  And of course as a result the subprocess takes much
longer to complete.

Even doing something as innocuous as (run (ed)) causes this to happen
(even with "ed" just sitting there in interactive mode, doing
nothing).

This is scsh version 0.6.7, running on a Debian GNU/Linux system,
version 5.0 ("lenny").  I used to run this on version 4.0 ("etch") of
Debian, and there it works fine.  Both of them seem to be scsh version
0.6.7, so I suppose there must be some difference in some underlying
library between the two systems.

Does anyone have a clue as to how I could start to figure out what
might be going wrong?  I'm really spoiled now: I'd hate to have to go
back to writing scripts in shell.  But of course this makes scsh
pretty close to unusable.


Hmm, this is interesting.  I just noticed that if I use run/string or
run/strings, instead of the plain "run", it all works fine -- no huge
CPU utilization.  Perhaps that's a clue?  I guess I could use those as
alternatives in some situations, but sometimes I would like to get the
exit status of the subprocess.

Cheers,
 - arb