Re: [matplotlib-devel] backend_driver errors

[Paul K. <pki...@ni...>]

On Wed, Sep 05, 2007 at 01:40:02PM +0300, Jouni K. Seppänen wrote:
> Paul Kienzle <pki...@ni...> writes:
> 
> [segfaults]
> > Is there something in the last couple of weeks which might cause this?
> 
> Some changes in font handling caused segfaults for me, and it turned out
> to be a bug in an old version of freetype:
> 
> http://article.gmane.org/gmane.comp.python.matplotlib.general/10062
> 
> Try running python under gdb, or using strace/truss/ktrace to see what
> is happening right before the segfault.

Running gdb first:

 Program received signal EXC_BAD_ACCESS, Could not access memory.
 Reason: KERN_INVALID_ADDRESS at address: 0x65c4a402
 0x65c4a402 in ?? ()
 (gdb) bt
 #0  0x65c4a402 in ?? ()
 #1  0x0265c5e1 in FT_Glyph_Get_CBox (glyph=0x54463a3a, bbox_mode=1634552114, acbox=0x6567) at /Users/pkienzle/Packages/freetype-2.3.5/src/base/ftglyph.c:534
 Previous frame inner to this frame (corrupt stack?)

So the problem seems to be in freetype.

The link above says:

 Looks like a freetype bug: the following code segfaults when linked
 against libfreetype.6.3.10 but not when linked against
 libfreetype.6.3.16. Freetype has some code to read dfont files, which
 apparently had a bug in the older version, and this is triggered by the
 new code that reads in all font files.

I don't understand why it is referring to 6.3.16 when 2.3.5 was released
in July 2007, unless 6.3.16 means May 16, 2006.

	- Paul