REWRITE_INVOKE_MAX and "query may contain cycles"

I've run into a situation where I need a RULE to execute more than 10
(guaranteed non-cyclical) operations.

In the mean time, outside of modifying the source every time I
compile/install postgres, how can I redefine REWRITE_INVOKE_MAX?

FWIW, I'm (still) using 7.2.3 on unix.

thanks!

eric