Re: [Discuss-gnuradio] Question about gnuradio-companion

[Andy Walls]

> On Mon, May 6, 2013 at 10:34 AM, Bennett, David S. (Scott)
> <address@hidden> wrote:
> >>
> >> Yes, you're using the absolute path. I was just checking to see if you 
> >> might
> >> have been trying to create a file in a write-protected directory or a 
> >> place 
> >> that
> >> didn't actually exist, which could have been a result of using a relative 
> >> path
> >> and having GRC point to a place you weren't expecting.
> >>
> >> But with this info, I'm not sure. That's not an error that GNU Radio is
> >> producing; it's the OS. If you replace the file sink with something else 
> >> (like a
> >> null sink), do you get the same error? I'm just checking here to see if 
> >> it's 
> >> a
> >> problem with the file you are trying to open or maybe complaining about
> >> something else.
> >>
> >> Tom
> >
> > I just replaced the file sync with a null sync, and I still get that error 
> > in 
> > gnuradio companion.  But as before if I execute the python script companion 
> > generates, it executes fine.  So I'm not sure what's going on.
> >
> > In doing some additional troubleshooting over the last few minutes, though, 
> > I 
> > hooked up a WX GUI FFT sync just to see if I could see something in the 
> > band 
> > I was looking at.  I had forgotten that I set the "generate options" to "No 
> > GUI" since I wasn't using a GUI.  So it didn't execute properly.  
> > Curiously, 
> > when I changed that option to WX GUI, and the FFT then worked, I went back 
> > and replaced it with the null sync, and now strangely it works.  And now 
> > the 
> > file sink works as well.  So there must be something in the generate 
> > options 
> > that behaves differently in companion than in python.
> >
> > This seems to be an adequate workaround.  Is there anything inherently 
> > wrong 
> > with setting GUI options when you're not using a GUI?
> >
> > Thanks,
> > Scott
> 
> You shouldn't have to work around this, though. Sounds like something
> small but funky going on in your system. But to your other question,
> no, there's nothing wrong with using a GUI option with no GUI
> components. It'll just pop up a small dialog box somewhere, though,
> and that could be annoying. May also be a problem if trying to
> remotely log in and run the app.
> 
> Tom

I just ran into Scott's problem.

The problem is not that gnuradio-companion's popen() of .../top_block.py
is failing, it's that the popen() of the xterm executable, xterm, is
failing.

gnuradio-companion tries to open an xterm when you have a "No GUI" top
block.

$ sudo yum install xterm 

solved the problem for me.

Regards,
Andy