> gdb kcalc  
GNU gdb (GDB; openSUSE 11.1) 6.8.50.20081120-cvs              
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This GDB was configured as "x86_64-suse-linux".                              
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<http://bugs.opensuse.org/>...                                               
(no debugging symbols found)                                                 
(gdb) set args --graphicssystem opengl                                       
(gdb) run                                                                    
Starting program: /usr/bin/kcalc --graphicssystem opengl                     
(no debugging symbols found)                                                 
(no debugging symbols found)                                                 
(no debugging symbols found)                                                 
[Thread debugging using libthread_db enabled]                                
using visual class 4, id c1                                                  
Mesa: Mesa 7.6-devel DEBUG build Aug 26 2009 11:37:05                        
Mesa warning: software DXTn compression/decompression available              
Mesa: Initializing x86-64 optimizations                                      
Mesa: 3Dnow! detected                                                        
Mesa warning: software DXTn compression/decompression available              
Mesa: Initializing x86-64 optimizations                                      
Mesa: 3Dnow! detected                                                        
QGLPixelBuffer: Unable to find a context/format match - giving up.           
QGLWindowSurface: Failed to create valid pixelbuffer, falling back           
Mesa warning: software DXTn compression/decompression available              
Mesa: Initializing x86-64 optimizations                                      
Mesa: 3Dnow! detected                                                        
hijackWindow() context created for KCalculator(0xa5deb0, name = "MainWindow#1") 1
Allocating 298 x 279 radeon RBO (pitch 304)

Program received signal SIGSEGV, Segmentation fault.
cs_gem_write_reloc (cs=0x1832080, bo=0x0, read_domain=2, write_domain=0, flags=0) at radeon_cs_gem.c:121
121         assert(bo->space_accounted);
(gdb) bt full
#0  cs_gem_write_reloc (cs=0x1832080, bo=0x0, read_domain=2, write_domain=0, flags=0) at radeon_cs_gem.c:121
        reloc = <value optimized out>
        idx = <value optimized out>
        i = <value optimized out>
        __PRETTY_FUNCTION__ = "cs_gem_write_reloc"
#1  0x00007ffff62f4052 in r300_swtcl_flush (ctx=<value optimized out>, current_offset=1120) at /usr/include/drm/radeon_cs.h:129
        rmesa = (r300ContextPtr) 0xf31940
        __FUNCTION__ = "r300_swtcl_flush"
#2  0x00007ffff62fefd2 in rcommon_flush_last_swtcl_prim (ctx=0x1100190) at radeon_dma.c:419
        rmesa = (radeonContextPtr) 0xf31940
        __FUNCTION__ = "rcommon_flush_last_swtcl_prim"
        __PRETTY_FUNCTION__ = "rcommon_flush_last_swtcl_prim"
#3  0x00007ffff62f49f5 in r300ChooseSwtclVertexFormat (ctx=<value optimized out>, _InputsRead=0x7fffffff39fc, _OutputsWritten=0x7fffffff39f8)
    at r300_swtcl.c:217
        rmesa = (r300ContextPtr) 0xf31940
        tnl = (TNLcontext *) 0x13ddbd0
        first_free_tex = 1
        InputsRead = 1
        OutputsWritten = 1
        num_attrs = 1
        fp_reads = 1
#4  0x00007ffff62f4db2 in r300RenderStart (ctx=0x1100190) at r300_swtcl.c:230
        rmesa = (r300ContextPtr) 0xf31940
#5  0x00007ffff63d0f8e in run_render (ctx=0x1100190, stage=0x0) at tnl/t_vb_render.c:275
        tnl = (TNLcontext *) 0x13ddbd0
        tab = <value optimized out>
        pass = <value optimized out>
        __PRETTY_FUNCTION__ = "run_render"
#6  0x00007ffff63c538f in _tnl_run_pipeline (ctx=0x1100190) at tnl/t_pipeline.c:158
        tnl = (TNLcontext *) 0x13ddbd0
        i = 8
#7  0x00007ffff63c59a4 in _tnl_draw_prims (ctx=0x1100190, arrays=<value optimized out>, prim=0x7fffffff3ce0, nr_prims=1, ib=0x0,
    min_index=<value optimized out>, max_index=<value optimized out>) at tnl/t_draw.c:445
        bo = {0x0 <repeats 26 times>, 0x100000000000000, 0x7ffff63b6c78, 0x6c6e30, 0x1100190, 0xf31940, 0x7ffff63b6c78, 0x3f0282833f028283}
        nr_bo = 0
....