appStocQt example does not run after building and installing Qt

I clone the whole qt5 supermodule and then

• configure -debug -make examples -prefix /path/to/dest, among other flags.
• ninja
• ninja install
• cd /path/to/dest/examples/demos/stocqt
• ./appStocQt (note that this executable is the only file the directory)

  qrc:/Main.qml:5:1: module "content" is not installed 
       import content 
       ^
  Requested MSAA sample count 8 but supported sample counts are QList(1, 2, 4) , using sample count 4 instead
  

• Only a small empty window shows up