keyboard related selftests crash on SLES 12

agent:2020/04/20 09:05:27 build.go:253: FAIL!  : tst_Selftests::runSubTest(keyboard stdout txt + txt) 'proc.exitStatus() == QProcess::NormalExit' returned FALSE. (Error running keyboard/keyboard -o -,txt -o /tmp/tst_selftests.pjbhBS/test_output.txt,txt with environment DISPLAY=:0 HOME=/home/qt PATH=/home/qt/work/install/bin:/opt/emsdk/emscripten-llvm-e1.38.16/:/opt/emsdk/node-v8.9.1-linux-x64/bin:/opt/emsdk/emscripten-1.38.16:/opt/cmake-3.7.2/bin:/opt/emsdk/emscripten-llvm-e1.38.16/:/opt/emsdk/node-v8.9.1-linux-x64/bin:/opt/emsdk/emscripten-1.38.16:/opt/cmake-3.7.2/bin:/home/qt/bin:/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games:/opt/squish/squish-6.4.3/bin:/opt/squish/squish-6.4.3/bin QT_LOGGING_RULES=*.debug=true;qt.*=false USER=qt XAUTHLOCALHOSTNAME=10-215-100-67 XDG_CONFIG_DIRS=/etc/xdg XDG_CURRENT_DESKTOP=GNOME-Classic:GNOME XDG_DATA_DIRS=/usr/share:/opt/cmake-3.7.2/share XDG_MENU_PREFIX=gnome- XDG_RUNTIME_DIR=/run/user/1000 XDG_SEAT=seat0 XDG_SESSION_ID=1 XDG_VTNR=7: Crashed: Process crashed: No protocol specified
 agent:2020/04/20 09:05:27 build.go:253: This application failed to start because no Qt platform plugin could be initialized.
 agent:2020/04/20 09:05:27 build.go:253:    Loc: [../tst_selftests.cpp(706)]