Running 8 building 10 gives "Out of file descriptors" ?

[Ian Lepore]

On Tue, 2014-11-18 at 18:22 -0800, Dieter BSD wrote:
> > I've been building 10.x and 11.x world and kernel from source on an 8.2
> > (and more recently now 8.4) system for a couple years, as recently as
> > last night.  I've never needed to do anything special.  When I check
> > sysctl kern.maxfiles it's set to 12328, not so different from yours.
> >
> > I wonder if some long-running process on your system is leaking away
> > descriptors?  A 'procstat -af' might help find that.
> 
> Uptime is less than 3 days.  (System hung a couple days ago, shutting off
> the signal to the display.  No core dump.  No clues as to *why* it hung.
> *grumble* )
> 
> >> getdtablesize() returned 11095
> 
> kern.maxfiles: 12328
> 
> # procstat -af | wc -l
>     1912
> 
> I ran
>    while true ; do procstat -af | wc -l; sleep 0.03 ; done
> in one window, and
>    make kernel-toolchain
> in another window.  Never got above 2000.  Not absolute proof, but
> it looks like it is not really running out of descriptors.
> 
> chmod 0 /usr/bin/mkdep
> gives the expected permission denied. (proves that it is trying to
> run /usr/bin/mkdep)
> 
> Restore the mode and change /usr/bin/mkdep to
>   #!/bin/sh
>   echo hello from mkdep
> and I'm back to "Out of file descriptors".  And it doesn't print hello.
> 
> So... make (I assume?) thinks (incorrectly?) that it is running out of
> file descriptors attempting to run /usr/bin/mkdep?

Oh.  Hrm.  The only thing in the source that says that exact message is
in /bin/sh input.c, and it looks like this:

		fd2 = fcntl(fd, F_DUPFD_CLOEXEC, 10);
		close(fd);
		if (fd2 < 0)
			error("Out of file descriptors");

So you have guess what the actual error is, or hack the code to print
errno or something.

-- Ian