https://www.virtualbox.org/changeset/90377/vbox
https://bugs.gentoo.org/805350
https://bugs.gentoo.org/805365

--- VirtualBox-6.1.26/configure
+++ VirtualBox-6.1.26/configure
@@ -1624,6 +1624,8 @@ EOF
         else
           # Strip .../QtCore as we add components ourself:
           INCQT5=`echo "$INCQT5"|$KBUILD_SED 's|\([^ ]*\)/QtCore|\1|g; s| $||g'`
+          # Strip .../QtGui as we add components ourself:
+          INCQT5=`echo "$INCQT5"|$KBUILD_SED 's|\([^ ]*\)/QtGui|\1|g; s| $||g'`
           # store only the first path, remove all other paths
           # most likely pkg-config gave us -I/usr/include/qt5 -I/usr/include/qt5/QtCore
           INCQT5=`echo "$INCQT5"|$KBUILD_SED 's|\([^ ]*\) .*|\1|'`