Compile error in qtbase/examples/opengl/hellowindow/hellowindow.h (#2)

Qt was configured with NO OpenGL support.

Compile error is:

In file included from /tmp/e2/build/qt-everywhere-opensource-src-5.4.0-alpha/qtbase/examples/opengl/hellowindow/hellowindow.cpp:41:0:
/tmp/e2/build/qt-everywhere-opensource-src-5.4.0-alpha/qtbase/examples/opengl/hellowindow/hellowindow.h:86:5: error: 'QOpenGLShaderProgram' does not name a type
QOpenGLShaderProgram *m_program;
^
/tmp/e2/build/qt-everywhere-opensource-src-5.4.0-alpha/qtbase/examples/opengl/hellowindow/hellowindow.h:87:5: error: 'QOpenGLBuffer' does not name a type
QOpenGLBuffer m_vbo;

Cause:

http://code.qt.io/cgit/qt/qtbase.git/tree/examples/examples.pro?h=5.8

After a code restructuring, line 17 of tree/examples/examples.pro does not verify if the configuration option opengl is enabled when building the OpenGL samples. This causes the error explained above when OpenGL has been disabled.

qtHaveModule(gui): SUBDIRS += gui opengl

The original bug report: https://bugreports.qt.io/browse/QTBUG-41200