Program received signal SIGSEGV, Segmentation fault.
0xb7656938 in pixman_region_union () from /usr/lib/libpixman-1.so.0
(gdb) bt
#0  0xb7656938 in pixman_region_union () from /usr/lib/libpixman-1.so.0
#1  0xb71ca2a4 in RegionUnion (migrate=<value optimized out>, pValidDst=<value optimized out>, pValidSrc=0x9435a80, transfer=0xb72e1860 <EVERGREENDownloadFromScreen>, fallback_index=1, 
    sync=0xb71c8190 <exaWaitSync>) at ../../include/regionstr.h:209
#2  exaCopyDirty (migrate=<value optimized out>, pValidDst=<value optimized out>, pValidSrc=0x9435a80, transfer=0xb72e1860 <EVERGREENDownloadFromScreen>, fallback_index=1, sync=0xb71c8190 <exaWaitSync>)
    at ../../exa/exa_migration_classic.c:126
#3  0xb71ca825 in exaCopyDirtyToSys (migrate=0x0) at ../../exa/exa_migration_classic.c:281
#4  0xb71cce6b in exaPrepareAccessReg_mixed (pPixmap=0x9435a10, index=0, pReg=0x0) at ../../exa/exa_migration_mixed.c:254
#5  0xb71d84e9 in ExaPrepareCompositeReg (op=12 '\f', pSrc=0x9435b98, pMask=0x0, pDst=0x9435aa0, xSrc=0, ySrc=0, xMask=0, yMask=0, xDst=0, yDst=0, width=9, height=9) at ../../exa/exa_unaccel.c:599
#6  ExaCheckComposite (op=12 '\f', pSrc=0x9435b98, pMask=0x0, pDst=0x9435aa0, xSrc=0, ySrc=0, xMask=0, yMask=0, xDst=0, yDst=0, width=9, height=9) at ../../exa/exa_unaccel.c:624
#7  0xb71d590b in exaCompositeRects (op=<value optimized out>, pSrc=0x9435b98, pMask=0x0, pDst=0x9435aa0, nrect=1, rects=0xbf8f57ac) at ../../exa/exa_render.c:613
#8  0xb71d1885 in exaGlyphsToMask (op=3 '\003', pSrc=0x9435520, pDst=0x9435100, maskFormat=0x91b8728, xSrc=10, ySrc=18, nlist=1, list=0xbf8f7170, glyphs=0xbf8f6d74) at ../../exa/exa_glyphs.c:621
#9  exaGlyphs (op=3 '\003', pSrc=0x9435520, pDst=0x9435100, maskFormat=0x91b8728, xSrc=10, ySrc=18, nlist=1, list=0xbf8f7170, glyphs=0xbf8f6d74) at ../../exa/exa_glyphs.c:842
#10 0x08122ae9 in damageGlyphs (op=76 'L', pSrc=0x9435520, pDst=0x9435100, maskFormat=0x91b8728, xSrc=<value optimized out>, ySrc=<value optimized out>, nlist=1, list=0xbf8f7170, glyphs=0xbf8f6d70)
    at ../../../miext/damage/damage.c:718
#11 0x081bea90 in CompositeGlyphs (op=0 '\000', pSrc=0x9435520, pDst=0x9435100, maskFormat=0x91b8728, xSrc=<value optimized out>, ySrc=<value optimized out>, nlist=1, lists=0xbf8f7170, glyphs=0xbf8f6d70)
    at ../../render/glyph.c:604
#12 0x0811c463 in ProcRenderCompositeGlyphs (client=0x946b128) at ../../render/render.c:1435
#13 0x08118293 in ProcRenderDispatch (client=0x9435a4c) at ../../render/render.c:2051
#14 0x0806e087 in Dispatch () at ../../dix/dispatch.c:432
#15 0x080625ba in main (argc=6, argv=0xbf8f7604, envp=0xbf8f7620) at ../../dix/main.c:291