[plt-scheme] More into on install fail of trunk on FreeBSD-7-amd64

Further to yesterday's (not terribly helpful) message: I found
why I wasn't getting useful symbols: I was gdb'ing against the
shell script mzscheme3m launcher.  I've re-svn'd and re-built,
and it crashed again in the private-yacc in the Algol60
collection.  Now I've got gdb happy, I can see that the stoppage
was an assertion failure (ABORT from kill, from within the
signal handler.  I don't think that I'm going to be very useful
here though, because the call stack is 490 frames deep, and
(based on some of the function names that *are* resolved) it's
running jit-compiled code.  I'm stumped, for now.  I can supply
the full stack trace, if that would be useful.

[For reference: I just re-build 372, and that worked fine, so I
don't think that the breakage is necessarily in FreeBSD...]

Cheers,

-- 
Andrew