Hanging at open-input-pipe now and then

[Roland Orre]

Lately it happens quite often that I get a hanging (in 1.7), but
breakable, when doing somthing like:

(let* ((in0 (open-input-pipe (string-append "zcat " fname)))
       (buf (read-line in0))
       (in (begin
             (close-pipe in0)
             (open-input-pipe (string-append "zcat " fname))))
       )

This hanging can occur rather soon after a restart. When it starts to
happen it will happen again after every 2-20 tries. When the hanging
does not start to happen I can do this several tousand times in a row
without problems.

I haven't investigated this very deeply yet, but just an observation.
The guardian pipe-guardian used in ice-9/popen.scm always have two
reachable pointers after gc, despite the pointers can't be reached.

Anyone else having similar problems?

        Best regards
        Roland Orre