OS: Sonoma 14.2.1 (23C71), I am porting a linux code (that uses C++, QT) to mac OS. after compiling the code on mac, I get segmentation error due to libGL.dylib. My question is how to avoid the segmentation error. debug messages when I run it using lldb: 2024-03-21 13:13:17.957964+0530 EdgeMarker[10094:150997] SecTaskCopyDebugDescription: EdgeMarker[10094]/0#-1 LF=0 2024-03-21 13:13:18.962117+0530 EdgeMarker[10094:150997] SecTaskLoadEntitlements failed error=22 cs_flags=20, pid=10094 2024-03-21 13:13:18.962246+0530 EdgeMarker[10094:150997] SecTaskCopyDebugDescription: EdgeMarker[10094]/0#-1 LF=0 Process 10094 stopped * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0xa80) frame #0: 0x00007ffa1c1295a4 libGL.dylib`glViewport + 22 libGL.dylib`glViewport: -> 0x7ffa1c1295a4 <+22>: movq 0xa80(%rax), %r9 0x7ffa1c1295ab <+29>: movq (%rax), %rdi 0x7ffa1c1295ae <+32>: popq %rbp 0x7ffa1c1295af <+33>: jmpq *%r9 Target 0: (EdgeMarker) stopped. Backtrace snippet: * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0xa80) * frame #0: 0x00007ffa1c1295a4 libGL.dylib`glViewport + 22 frame #1: 0x000000010000c427 EdgeMarker`MyGLCanvas::initializeGL(this=0x00007f8e4f857710) at MyGLCanvas.cpp:33:2 The error occurs when initializing an opengl window: void MyGLCanvas::initializeGL() { m_width = this->frameGeometry().width(); m_height = this->frameGeometry().height(); m_initialized = true; m_Eye[0] = 0.0f; m_Eye[1] = 0.0f; m_Eye[2] = -2.0f; //Actual code m_PerspectiveAngleDegrees = 45.0f; m_NearPlane = 0.01f; m_FarPlaneOffset = 100.0f; glViewport(0, 0, (GLint)m_width, (GLint)m_height); Before calling MyGLcanvas::initializeGL() there is a call to setFocus() function. SetFocus is a function used in GUI programming to give focus to a specific window or control within a window. My second question : Is setFocus valid is mac OS or is there an equivalent?