Could you confirm that it works on OpenBSD and that there’s no
performance regression?

Andrew: it removes the /proc/self/fd loop you added to fix
<https://bugs.gnu.org/59321>, but it reduces the number of ‘close’ calls
in the child.  Could you check whether that’s okay performance-wise?

Eventually I plan to use ‘posix_spawn_file_actions_addclosefrom_np’ on
glibc >= 2.34, but I have yet to test it.  That will be the best
solution.

Josselin: I simplified the ‘dup2’ logic somewhat.

Feedback welcome!

> The regress passes and while this workaround may be temporarly
> acceptable I -personally- don't like it much.  There's a reason guile
> can't set CLOEXEC for all the file descriptors > 2 obtained via open,
> socket, pipe, ... like perl -for example- does?

Guile does that for file descriptors it opens internally, but
applications using ‘open-file’ without the recently-added “e” flag, or
‘socket’ without ‘SOCK_CLOEXEC’, etc., end up with more file descriptors
that need to be taken care of.

I wish the default were close-on-exec, but we’re not there yet.

Thanks,
Ludo’.