compile error with Qwt 6.3 / 6.4

[limann77]

What is the bug or the crash?

[ 74%] Linking CXX shared library ../../output/lib/libqgis_gui.so
/usr/bin/ld: CMakeFiles/qgis_gui.dir/raster/qgsrasterhistogramwidget.cpp.o: in function `QgsRasterHistogramWidget::refreshHistogram()':
qgsrasterhistogramwidget.cpp:(.text+0x4650): undefined reference to `QwtPlotCurve::setSamples(QList<QPointF> const&)'
/usr/bin/ld: qgsrasterhistogramwidget.cpp:(.text+0x4953): undefined reference to `QwtPlotHistogram::setSamples(QList<QwtIntervalSample> const&)'
/usr/bin/ld: CMakeFiles/qgis_gui.dir/qgscurveeditorwidget.cpp.o: in function `QgsCurveEditorWidget::updateHistogram()':
qgscurveeditorwidget.cpp:(.text+0x17b5): undefined reference to `QwtPlotHistogram::setSamples(QList<QwtIntervalSample> const&)'
/usr/bin/ld: CMakeFiles/qgis_gui.dir/qgscurveeditorwidget.cpp.o: in function `QgsCurveEditorWidget::updatePlot()':
qgscurveeditorwidget.cpp:(.text+0x25d8): undefined reference to `QwtPlotCurve::setSamples(QList<QPointF> const&)'
/usr/bin/ld: CMakeFiles/qgis_gui.dir/qgsgradientcolorrampdialog.cpp.o: in function `QgsGradientColorRampDialog::updatePlot()':
qgsgradientcolorrampdialog.cpp:(.text+0x2451): undefined reference to `QwtPlotCurve::setSamples(QList<QPointF> const&)'
/usr/bin/ld: qgsgradientcolorrampdialog.cpp:(.text+0x2461): undefined reference to `QwtPlotCurve::setSamples(QList<QPointF> const&)'
/usr/bin/ld: qgsgradientcolorrampdialog.cpp:(.text+0x2471): undefined reference to `QwtPlotCurve::setSamples(QList<QPointF> const&)'
/usr/bin/ld: qgsgradientcolorrampdialog.cpp:(.text+0x2481): undefined reference to `QwtPlotCurve::setSamples(QList<QPointF> const&)'
/usr/bin/ld: CMakeFiles/qgis_gui.dir/qgshistogramwidget.cpp.o: in function `QgsHistogramWidget::drawHistogram()':
qgshistogramwidget.cpp:(.text+0x159f): undefined reference to `QwtPlotHistogram::setSamples(QList<QwtIntervalSample> const&)'
/usr/bin/ld: qgshistogramwidget.cpp:(.text+0x1a58): undefined reference to `QwtPlotHistogram::setSamples(QList<QwtIntervalSample> const&)'
collect2: Fehler: ld gab 1 als Ende-Status zurück
make[2]: *** [src/gui/CMakeFiles/qgis_gui.dir/build.make:14270: output/lib/libqgis_gui.so.3.99.0] Fehler 1

Steps to reproduce the issue

Build QGIS with

    cmake -G "Unix Makefiles" ../ \
        -DCMAKE_INSTALL_PREFIX=/usr \
        -DQGIS_MANUAL_SUBDIR=share/man \
        -DENABLE_TESTS=FALSE \
        -DWITH_GEOREFERENCER=TRUE \
        -DWITH_3D=FALSE \
        -DWITH_SERVER=FALSE \
        -DWITH_GLOBE=FALSE \
        -DWITH_EPT=TRUE \
        -DWITH_COPC=TRUE \
        -DWITH_PDAL=TRUE \
        -DWITH_INTERNAL_LAZPERF=TRUE \
        -DWITH_QWTPOLAR=TRUE \
        -DQWTPOLAR_LIBRARY=/usr/lib/libqwt.so \
        -DQWTPOLAR_INCLUDE_DIR=/usr/include/qwt \
        -DWITH_INTERNAL_QWTPOLAR=FALSE \
        -DBUILD_WITH_QT6=TRUE \
        -DBUILD_WITH_QT5=FALSE \
        -DWITH_QTWEBKIT=FALSE \
        -DQSCINTILLA_INCLUDE_DIR=/usr/include/qt6/Qsci \
        -DHAVE_QTSERIALPORT=FALSE
cmake --build .

Versions

QGIS: git master 57dc9b3

QWT: 6.3.0 or 6.4.0 (SourceForge git master)

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

Doesn't apply: New profile (build error)

• I tried with a new QGIS profile

Additional context

No response

[limann77]

A build with -DWITH_INTERNAL_QWTPOLAR=TRUE \

yields the same error for me:

qgshistogramwidget.cpp:(.text+0x159f): undefined reference to `QwtPlotHistogram::setSamples(QList<QwtIntervalSample> const&)'

Qt 5.15.18 & 6.9.2 are present

[hadallen]

I believe you need to have qwt built with qt6. on archlinux I needed to use qwt-qt6 to get it to build properly when using BUILD_WITH_QT6=TRUE

edit: also, I needed to link to the proper lib files after installing qwt-qt6:

    # in my cmake flags...
    -DQWTPOLAR_LIBRARY=/usr/lib/libqwt-qt6.so \
    -DQWTPOLAR_INCLUDE_DIR=/usr/include/qwt-qt6 \
    #...