Re: Qt/gui on MacOSX (was: 4.0 release goals)

[Ben Abbott]

On Nov 4, 2012, at 8:58 PM, Michael Goffioul wrote:

> On Sun, Nov 4, 2012 at 6:40 PM, Ben Abbott <address@hidden> wrote:
> > Since the gui build process was integrated into the CLI build process, the 
> > gui has not run under MacOS X.  I'm not certain, but I think gnuplot had a 
> > similar problem.
> >
> >         http://www.digipedia.pl/usenet/thread/12789/10528/#post10548
> >
> > When I try to run the gui, I get the error below (repeated 16 times).  
> > Which is the same error encountered by the gnuplot developers.
> >
> > The process has forked and you cannot use this CoreFoundation functionality 
> > safely. You MUST exec().
> > Break on 
> > __THE_PROCESS_HAS_FORKED_AND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONALITY___YOU_MUST_EXEC__()
> >  to debug.
> >
> > Fixing this is beyond my abilities. but I can test patches.
> >
> >
> > I've had a quick look and my understanding is that somewhere we use a 
> > CoreFoundation API before forking, which is not allowed by Mac OS X (God 
> > knows why...), if you also want to use CF API after forking.
> >
> > AFAIK there aren't many places in octave where there's a direct access to 
> > the underlying graphics system, one of them is display_info class. Indeed, 
> > this class is used before forking, in octave_starting_gui 
> > (libinterp/octave.cc). So as  first try, you could edit src/main.cc and 
> > replace the call to octave_start_gui() with true to see whether it makes 
> > any difference.
> >
> > Michael.
> 
> Definitely made a difference, but I can't tell if it is an improvement or not.
> 
> The error no longer shows up, but neither Octave nor the gui starts either.  
> There is just a short delay and the shell prompt returns.
> 
> Sigh.... Mac OS X is definitely "different". Try to run in gdb, maybe you'll 
> get some useful backtrace or information.
> 
> Michael.

Hmmm ... looks like something is broken.  The line below exists with no error 
or warning.

        ./run-octave --force-gui --debug

Ben