Description: Add QtWidgets and QtGui explicitly as required Qt libraries.
Author: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

--- a/OpenBoard.pro
+++ b/OpenBoard.pro
@@ -39,6 +39,8 @@
 QT += multimediawidgets
 QT += webenginewidgets
 QT += printsupport
+QT += widgets
+QT += gui
 QT += core
 QT += concurrent
 greaterThan(QT_MAJOR_VERSION, 5): win32: QT += core5compat