GNU readline in Racket

My main operating system is Gentoo (2.6.32-gentoo-r7), which doesn't have the Racket programming language in its package repository, so I compiled it myself from the sources available on the racket website (another side note: Racket v5.0.1 won't compile if you have a newer version of libpng installed, but Racket v5.0.2 fixes the out-of-date function call). However, I ran into a slight problem when trying to install GNU Readline support by evaluating (require readline) in the racket prompt, where I was greeted by the following error:

ffi-lib: couldn't open "libreadline.so.5" (libreadline.so.5: cannot open shared object file: No such file or directory)

Which sounds rather foreboding, but fortunately has an easy fix. The problem is caused by a tendency of later GNU Readline installations to lack the shared object file named "libreadline.so.5", instead having a file named "libreadline.so.6", a newer version of the library. The simple (and as far as I have been able to tell, correct) fix is to modify line 11 in $RACKET_DIR/lib/racket/collects/readline/mzrl.rkt from:

(define libreadline (ffi-lib "libreadline" '("5" "4" ""))) 

to

(define libreadline (ffi-lib "libreadline" '("6" "5" "4" ""))).

Hope that keeps at least one Schemer from pulling their hair out in the near future.