[racket] Limit command-line Racket's memory

Hi all,

I'm running racket (from git) from the command-line on a machine with 
64MB RAM. The 3m collector is not (yet) supported on the machine - it's 
a MIPS-based CPU.

When I start the web-server, it loads and runs OK up until it tries to 
fork() for a (process*) call, at which point it fails with out-of-memory 
since it has only left about 1MB for the rest of the system.

Is there some way of limiting the memory Racket will try to use to, say, 
32MB? Perhaps an environment variable, command-line flag or compile-time 
preprocessor definition?

Regards,
   Tony