Consider the following example: (use-modules (ice-9 popen))
(parameterize ((current-error-port (%make-void-port OPEN_BOTH)))
(while #t
(close-pipe (open-pipe* OPEN_READ "free"))
(sleep 1)))
This opens a new "/dev/null" file descriptor every second and doesn't
close it when close-pipe is called.
If current ports are all fd ports, this doesn't happen.
AFAICT the problem was introduced by the commit
36fd2b4920ae926c79b936c29e739e71a6dff2bc in Guile 3.0.10.
