Freeciv

On Manjaro, with gcc-16 and Qt-6.11, S3_2 Qt-client compile fails on sprite.cpp:

In file included from /usr/include/qt6/QtCore/qstring.h:15,
from /usr/include/qt6/QtCore/qcoreapplication.h:9,
from /usr/include/qt6/QtGui/qimagereader.h:9,
from /usr/include/qt6/QtGui/QImageReader:1,
from ../../../../src/client/gui-qt/sprite.cpp:19:
/usr/include/qt6/QtCore/qchar.h:48:31: error: defining 'QChar', which previously failed to be complete in a SFINAE context [-Werror=sfinae-incomplete=]
48 | class QT6_ONLY(Q_CORE_EXPORT) QChar { | ^_~~
In file included from /usr/include/c++/16.1.1/unordered_map:44,
from /usr/include/c++/16.1.1/functional:80,
from /usr/include/qt6/QtCore/qcomparehelpers.h:29,
from /usr/include/qt6/QtCore/qcompare.h:661,
from /usr/include/qt6/QtCore/qnamespace.h:14,
from /usr/include/qt6/QtCore/qbytearray.h:10,
from /usr/include/qt6/QtGui/qimagereader.h:8:
/usr/include/c++/16.1.1/bits/range_access.h:325:24: note: here. Use '-Wsfinae-incomplete=2' for a diagnostic at that point
325 | -> decltype(__cont.data()) | ~_~~~~^~~~