QXcbConnection: Could not connect to display

Usage: qmlscene [options] <filename> Options: --maximized ...................... Run maximized --fullscreen ..................... Run fullscreen --transparent .................... Make the window transparent --multisample .................... Enable multisampling (OpenGL anti-aliasing) --no-version-detection ........... Do not try to detect the version of the .qml file --slow-animations ................ Run all animations in slow motion --resize-to-root ................. Resize the window to the size of the root item --quit ........................... Quit immediately after starting --disable-context-sharing ........ Disable the use of a shared GL context for QtQuick Windows .........(remove AA_ShareOpenGLContexts) --desktop..........................Force use of desktop GL (AA_UseDesktopOpenGL) --gles.............................Force use of GLES (AA_UseOpenGLES) --software.........................Force use of software rendering (AA_UseOpenGLES) --verbose..........................Print version and graphical diagnostics for the run-time -I <path> ........................ Add <path> to the list of import paths -P <path> ........................ Add <path> to the list of plugin paths -translation <translationfile> ... Set the language to run in