[Pkg-octave-devel] Bug#743260: octave: fltk plotting segfaults when using llvmpipe direct rendering

[Mike Miller]

Control: severity -1 important

On Tue, Apr 01, 2014 at 00:56:53 -0400, Mike Miller wrote:
> On Tue, Apr 01, 2014 at 00:48:38 -0400, Mike Miller wrote:
> > Octave segfaults when plotting anything with the fltk toolkit when
> > Octave is built with JIT and when using one of the Gallium llvmpipe Mesa
> > drivers for direct rendering. JIT does not have to be enabled in Octave
> > for the crash to occur. This is perhaps some kind of LLVM conflict,
> > since Octave uses LLVM for JIT and Mesa uses LLVM for the software
> > rendering drivers.
> 
> I just looked again and noticed that Octave is built against LLVM-3.3
> while Mesa is built against LLVM-3.4. I will try to rebuild Octave
> against LLVM-3.4 and see if that also resolves this crash.

I was able to build Octave against LLVM 3.4 using the proof-of-concept
patch on the upstream bug tracker [1]. After installing and running some
simple plot tests, everything works for me, so it does look like this
library conflict is indeed what causes the segfault.

This bug affects all Octave users plotting with fltk, which is now the
Octave default, and who are using the free LLVM-based graphics drivers
for AMD and NVIDIA cards, the VMware virtual GPU, or the swrast driver.
Upgrading severity to important.

[1] https://savannah.gnu.org/bugs/index.php#comment11

-- 
mike