Unable to build from source on Linux

[Csokis]

Hi!

Unable to build from source on Linux. 😢

g++ -c -pipe -O3 -march=x86-64-v3 -flto -fno-fat-lto-objects -Wall -Wextra -D_REENTRANT -fPIC -DQT_DISABLE_DEPRECATED_BEFORE=0x050F00 -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -I/mnt/minden/Sources/m64p/mupen64plus-input-qt -I. -I/mnt/minden/Sources/m64p/mupen64plus-core/src/api -I/usr/local/include -I/usr/include/SDL2 -I/usr/local/include/SDL2 -I/usr/include/qt -I/usr/include/qt/QtWidgets -I/usr/include/qt/QtGui -I/usr/include/qt/QtNetwork -I/usr/include/qt/QtCore -I. -I/usr/lib/qt/mkspecs/linux-g++ -o main.o /mnt/minden/Sources/m64p/mupen64plus-input-qt/main.cpp
/mnt/minden/Sources/m64p/mupen64plus-input-qt/main.cpp:41:10: fatal error: QStringDecoder: No such file or directory
41 | #include
| ^~~~~~~~~~~~~~~~
compilation terminated.
make: *** [Makefile:1027: main.o] Error 1

Why does it look for the QStringDecoder file in /usr/include/qt/QtCore when it is in /usr/include/qt6/QtCore?! I don't understand! 😕

Arch Linux (5.18.9-arch1-1), QT5 and QT6 installed!