noexcept build errors after updating to 6.9.0

[GregB]

I am building a Qt console application in Linux and am getting build errors after updating Qt. I am building on RockyLinux 8.10. The program built fine with 6.6.3, but now I get the following errors after updating to 6.9.0

This error repeats over and over. The first and last lines of this snippet show the error.

../../../Qt/6.9.0/gcc_64/include/QtCore/qcomparehelpers.h:160:34: error: static assertion failed: Use *_NON_NOEXCEPT version of the macro, or make the helper function noexcept
     static_assert(!noexcept(f()) || noexcept(Func(lhs, rhs)), \
                   ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../Qt/6.9.0/gcc_64/include/QtCore/qoverload.h:72:32: note: in definition of macro ‘QT_VA_ARGS_EXPAND’
 #define QT_VA_ARGS_EXPAND(...) __VA_ARGS__ // Needed for MSVC
                                ^~~~~~~~~~~
../../../Qt/6.9.0/gcc_64/include/QtCore/qcomparehelpers.h:300:9: note: in expansion of macro ‘QT_COMPARISON_NOEXCEPT_CHECK’
         QT_COMPARISON_NOEXCEPT_CHECK(Noexcept, comparesEqual); \
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../Qt/6.9.0/gcc_64/include/QtCore/qcomparehelpers.h:470:5: note: in expansion of macro ‘QT_DECLARE_EQUALITY_OPERATORS_HELPER’
     QT_DECLARE_EQUALITY_OPERATORS_HELPER(LeftType, RightType, /* non-constexpr */, \
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../Qt/6.9.0/gcc_64/include/QtCore/qoverload.h:74:49: note: in expansion of macro ‘QT_DECLARE_EQUALITY_COMPARABLE_NON_NOEXCEPT_2’
 #define QT_OVERLOADED_MACRO_EXPAND(MACRO, ARGC) MACRO##_##ARGC
                                                 ^~~~~
../../../Qt/6.9.0/gcc_64/include/QtCore/qoverload.h:75:46: note: in expansion of macro ‘QT_OVERLOADED_MACRO_EXPAND’
 #define QT_OVERLOADED_MACRO_IMP(MACRO, ARGC) QT_OVERLOADED_MACRO_EXPAND(MACRO, ARGC)
                                              ^~~~~~~~~~~~~~~~~~~~~~~~~~
../../../Qt/6.9.0/gcc_64/include/QtCore/qoverload.h:76:59: note: in expansion of macro ‘QT_OVERLOADED_MACRO_IMP’
 #define QT_OVERLOADED_MACRO(MACRO, ...) QT_VA_ARGS_EXPAND(QT_OVERLOADED_MACRO_IMP(MACRO, QT_VA_ARGS_COUNT(__VA_ARGS__))(__VA_ARGS__))
                                                           ^~~~~~~~~~~~~~~~~~~~~~~
../../../Qt/6.9.0/gcc_64/include/QtCore/qcomparehelpers.h:495:5: note: in expansion of macro ‘QT_OVERLOADED_MACRO’
     QT_OVERLOADED_MACRO(QT_DECLARE_EQUALITY_COMPARABLE_NON_NOEXCEPT, __VA_ARGS__)
     ^~~~~~~~~~~~~~~~~~~
../../../Qt/6.9.0/gcc_64/include/QtCore/qjsonobject.h:326:5: note: in expansion of macro ‘Q_DECLARE_EQUALITY_COMPARABLE_NON_NOEXCEPT’
     Q_DECLARE_EQUALITY_COMPARABLE_NON_NOEXCEPT(QJsonObject, QJsonValue)
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../Qt/6.9.0/gcc_64/include/QtCore/qjsonobject.h: In function ‘bool operator==(const QJsonObject&, const QJsonValueConstRef&)’:
../../../Qt/6.9.0/gcc_64/include/QtCore/qcomparehelpers.h:160:34: error: static assertion failed: Use *_NON_NOEXCEPT version of the macro, or make the helper function noexcept
     static_assert(!noexcept(f()) || noexcept(Func(lhs, rhs)), \
                   ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

[Christian Ehrlicher]

What gcc version do you use? When does the error occour? By simply including a Qt header in a simple main.cpp or what else?

[GregB]

@Christian-Ehrlicher I'm using gcc 8.5.0
I honestly can't tell where in the code the error is occuring because the output is so long. I've been building this applciation for years using various versions of Qt, but I haven't seen these errors before. It builds without error under Qt 6.6.3.

I can try a simple program to see if I also get the errors there.

[jporcher]

@GregB : Have you fixed this issue? I'm experiencing the same kind of errors when I simply include <QApplication>

[Christian Ehrlicher]

Use a recent compiler, gcc 8 is not supported with Qt6 as you can see here: https://doc.qt.io/qt-6/supported-platforms.html