Using guile 2.1.3, I have a program that:

- reads urls from a text file
- download the urls using curl command via popen
- output the result to stdout

Also, it relies on n-for-each-par-map for ice-9 threads.

IMO, the most suspicious is the definition of the `curl' proc:


   (define (curl url)
      (let* ((port (open-input-pipe (format #f "curl -is \"~a\"" url)))
             (response (read-string port)))
        (close-pipe port)
        response))


I fail to see how this can leak.

To reproduce the bug you need a giant list of preferably different urls.
Such a list is available at http://hyperdev.fr/data/hn/hn.urls.txt.xz

You can run the test program with the following command:

    cat hn.urls.txt | guile urls-step00-fetch.scm > /dev/null

This is not the only program I tried on guile-2.1.3 that leaks but
it's the easiest to reproduce.

I will try to reproduce the bug on 2.0.12.