“jom.exe exited with code 2” when using headers outside of main.cpp

[SimonR]

I have some trouble getting my application running. When I include the header files for a third-party api, the program throws the following error:

This is my .pro file:

QT += quick

CONFIG += c++11

DEFINES += QT_DEPRECATED_WARNINGS


SOURCES += \
        db.cpp \
        main.cpp

RESOURCES += qml.qrc

QML_IMPORT_PATH =

QML_DESIGNER_IMPORT_PATH =

qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

HEADERS += \
    db.h

INCLUDEPATH += C:/mongo-cxx-driver-3.4.1/include/bsoncxx/v_noabi \
               C:/mongo-cxx-driver-3.4.1/include/mongocxx/v_noabi \
               D:/boost_1_72_0

LIBS += -LC:/mongo-cxx-driver-3.4.1/lib -lbsoncxx \
        -LC:/mongo-cxx-driver-3.4.1/lib -lmongocxx

The code in the file types.hpp at line 39:

enum class type : std::uint8_t {
#define BSONCXX_ENUM(name, val) k_##name = val,
#include <bsoncxx/enums/type.hpp>
#undef BSONCXX_ENUM
};

The strange thing is that when I write the class in the main.cpp file, it works. The program also works fine in VS2019.