How to identify a potential memory leak in guile programs?

[Hengqing Hu]

Dear list,

I wrote a small program in scheme interpreted by guile.
It is used to find identical code blocks in a file or directory.
The problem I have is, when the contents of directory is large,
the memory used by the program keeps increasing and finally
when memory is used up, I get the following error:
ERROR: In procedure primitive-fork:
ERROR: Cannot allocate memory

Can somebody help to look into the code and tell me what's wrong?
The guile version used is guile-1.8.8-5.fc18.2.x86_64 on fedora 18.

You can find the program here:
https://github.com/hudayou/fib

-- 
Best Regards, Hengqing Hu