[REG] qtserialport fails to compile on INTEGRITY

When compiling Qt 5.13 beta2 on INTEGRITY 19.0.0 for RCar Salvator-XS:

make[1]: Entering directory '/home/tiaarnip/src/qt513_shadow_salvator1918/qtserialport'
Some of the required modules (!integrity) are not available.
Skipped.
make[1]: Leaving directory '/home/tiaarnip/src/qt513_shadow_salvator1918/qtserialport'
cd qtserialbus/ && ( test -e Makefile || /home/tiaarnip/src/qt513_shadow_salvator1918/qtbase/bin/qmake -o Makefile /home/tiaarnip/src/qt5/qtserialbus/qtserialbus.pro ) && make -f Makefile
make[1]: Entering directory '/home/tiaarnip/src/qt513_shadow_salvator1918/qtserialbus'
cd src/ && ( test -e Makefile || /home/tiaarnip/src/qt513_shadow_salvator1918/qtbase/bin/qmake -o Makefile /home/tiaarnip/src/qt5/qtserialbus/src/src.pro ) && make -f Makefile
make[2]: Entering directory '/home/tiaarnip/src/qt513_shadow_salvator1918/qtserialbus/src'
cd serialbus/ && ( test -e Makefile || /home/tiaarnip/src/qt513_shadow_salvator1918/qtbase/bin/qmake -o Makefile /home/tiaarnip/src/qt5/qtserialbus/src/serialbus/serialbus.pro ) && make -f Makefile
Project MESSAGE: perl -w /home/tiaarnip/src/qt5/qtbase/bin/syncqt.pl -check-includes -module QtSerialBus -version 5.13.0 -outdir /home/tiaarnip/src/qt513_shadow_salvator1918/qtserialbus -builddir /home/tiaarnip/src/qt513_shadow_salvator1918/qtserialbus /home/tiaarnip/src/qt5/qtserialbus
<srcbase> = /home/tiaarnip/src/qt5/qtserialbus
<bldbase> = /home/tiaarnip/src/qt513_shadow_salvator1918/qtserialbus
<outbase> = /home/tiaarnip/src/qt513_shadow_salvator1918/qtserialbus
Project ERROR: Unknown module(s) in QT_PRIVATE: serialport
make[2]: *** [Makefile:50: sub-serialbus-make_first] Error 3
make[2]: Leaving directory '/home/tiaarnip/src/qt513_shadow_salvator1918/qtserialbus/src'
make[1]: *** [Makefile:49: sub-src-make_first] Error 2
make[1]: Leaving directory '/home/tiaarnip/src/qt513_shadow_salvator1918/qtserialbus'
make: *** [Makefile:237: module-qtserialbus-make_first] Error 2