Re: [Matplotlib-users] segfaults in ipython

[Fernando P. <Fer...@co...>]

Steve Schmerler wrote:

> I upgraded to IPython 0.6.15 (installed from source), the former 0.6.13 
> was apt-get installed on Debian (sarge, stable).
> 
> Actually, it is a segfault, and it kills the IPython shell.
> 
> ###############################################################################
> 
> elcorto@bach:~/Install/IPython$ ipython -pylab
> /usr/lib/python2.3/site-packages/IPython/Shell.py:627: 
> GtkDeprecationWarning: gtk.timeout_add is deprecated, use 
> gobject.timeout_add instead
>    self.gtk.timeout_add(self.TIMEOUT, self.on_timer)
> Python 2.3.5 (#2, May  4 2005, 08:51:39)
> Type "copyright", "credits" or "license" for more information.
> 
> IPython 0.6.15 -- An enhanced Interactive Python.
> ?       -> Introduction to IPython's features.
> %magic  -> Information about IPython's 'magic' % functions.
> help    -> Python's own help system.
> object? -> Details about 'object'. ?object also works, ?? prints more.
> 
>    Welcome to pylab, a matplotlib-based Python environment.
>    For more information, type 'help(pylab)'.
> 
> In [1]: plot([1,2,3])
> ---------------------------------------------------------------------------
> exceptions.SystemError                               Traceback (most 
> recent call last)
> 
> 
> SystemError: ../Objects/moduleobject.c:48: bad argument to internal function
> Speicherzugriffsfehler
> elcorto@bach:~/Install/IPython$
> 
> #################################################################################
> 
> At least "Speicherzugriffsfehler" is german for segfault :)
> 
> I still can plot as root, but not as user!? If it's some kind of 
> permission problem it would be good to know something about
> "../Objects/moduleobject.c". I there a way to get IPython to print the 
> full path?

No, unfortunately the string:

SystemError: ../Objects/moduleobject.c:48: bad argument to internal function

is being generated internally, so the path has already been truncated by 
somebody else.  IPython has no access to any more info than this, as that 
string is the value of the exception given to the ipython traceback handler. 
You can try setting '%xmode verbose' in ipython to produce more verbose 
tracebacks, but I doubt we'll see anything more meaningful in this particular 
case (since there don't seem to be any frames properly generated in the 
traceback).

This is really strange.  I can only suggest trying some of the other backends 
(QtAgg, TKAgg, WXAgg) and seeing what happens.  But we're really debugging in 
the dark here.

> BTW, Fernando mentioned earlier that this GtkDeprecationWarning would go 
> away if I upgrade to IPython 0.6.15 but unfortunately it's still there.

Sorry, I should have clarified that this change was made to SVN, _right after_ 
we released .15.  So only an SVN install would make it go away (or manually 
applying the relevant fix).  If it really bothers you, I can track down the 
exact changes needed for you.

Cheers,

f