Re: [Visualpython-users] Segmentation fault Python2.0/Visual Python (Vpython)

On Wed, 10 Jan 2001, Nils Wagner wrote:

> Hi,
> 
> I have installed Vpython on Linux (kernel 2.2.16)

[...snip...]

> If I run the Demoprograms which come with Vpython I get a segmentation
> fault
> 
Hum.

The installation sounded right.

First, I'm going to ask you to recompile your cvisualmodule.so to have
debugging symbols. to do this, edit the Makefile, and change the lines

CFLAGS =  -O3 -a -I. $(CXX_INCLUDES) $(PYTHON_INCLUDES) $(GTK_INCLUDES)
CXXFLAGS = -O3 -a -I. $(CXX_INCLUDES) $(PYTHON_INCLUDES) $(GTK_INCLUDES) -w

(towards the top) to 

CFLAGS =  -g -a -I. $(CXX_INCLUDES) $(PYTHON_INCLUDES) $(GTK_INCLUDES)
CXXFLAGS = -g -a -I. $(CXX_INCLUDES) $(PYTHON_INCLUDES) $(GTK_INCLUDES) -w

Then recompile (make clean first) and put the resulting cvisualmodule.so in
place.

Then do this:
  gdb python
to start gdb on python (it's python that's actually crashing). then
  run
to start the python interpreter (in interactive mode). then
  from visual import *
to load the visual library. it may crash there; if not try something simple 
like
  sphere()
(which will cause the display window to open and should draw a while gl
sphere).

If (when) it crashes, do a 
  backtrace 
in the debugger (which will come up when it catches the segfault) and paste
that back into an email. With the debugging info  enabled it'll tell you
exactly on which line it crashed, and which function called which function all
the way back down the call stack.

Hopefully i'll be able to figure out what's breaking from that :)

If none of that breaks it, then that means that only some demos are broken (i
know at least wave.py is most likely broken); just report that and i'll have
you try some other stuff.



cheers,

ari


i'm reminded of a saying (used to be my .signature): "You know how your life
flashes in front of your eyes when you die? That's just gdb unwinding the call
stack ... "