(gdb) bt
#0  0x12654690 in osg::GraphicsContext::releaseContext ()
#1  0x11bafd24 in osgUtil::RenderStage::draw ()
#2  0x11baaec4 in osgUtil::RenderStage::drawPreRenderStages ()
#3  0x11bba8a4 in osgUtil::SceneView::draw ()
#4  0x000086f4 in FGRenderer::update (refresh_camera_settings=true) at renderer.cxx:577
#5  0x00037d84 in GLUTdraw () at fg_os.cxx:128
#6  0x97e12438 in -[GLUTView drawRect:] ()
#7  0x97e122e4 in -[GLUTView handleWorkEvent:] ()
#8  0x97e2b61c in processWindowWorkList ()
#9  0x97e2b684 in __glutProcessWorkEvents ()
#10 0x97e1b1d8 in -[GLUTApplication run] ()
#11 0x97e2b954 in glutMainLoop ()
#12 0x00005628 in fgMainInit (argc=2, argv=0xbffffbdc) at main.cxx:1071
#13 0x00003c50 in main (argc=2, argv=0xbffffbdc) at bootstrap.cxx:220