Bug#974584: inspectrum FTBFS: error: aggregate ‘QPainterPath path’ has incomplete type and cannot be defined

[Helmut Grohne <helmut@subdivi.de>]

Source: inspectrum
Version: 0.2.2-1
Severity: serious
Tags: ftbfs

inspectrum fails to build from source in unstable on amd64:

| [ 84%] Building CXX object CMakeFiles/inspectrum.dir/traceplot.cpp.o
| /usr/bin/c++ -DQT_CONCURRENT_LIB -DQT_CORE_LIB -DQT_GUI_LIB -DQT_NO_DEBUG -DQT_WIDGETS_LIB -I/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu -I/<<PKGBUILDDIR>> -I/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/inspectrum_autogen/include -isystem /usr/include/x86_64-linux-gnu/qt5 -isystem /usr/include/x86_64-linux-gnu/qt5/QtCore -isystem /usr/lib/x86_64-linux-gnu/qt5/mkspecs/linux-g++ -isystem /usr/include/x86_64-linux-gnu/qt5/QtWidgets -isystem /usr/include/x86_64-linux-gnu/qt5/QtGui -isystem /usr/include/x86_64-linux-gnu/qt5/QtConcurrent -g -O2 -fdebug-prefix-map=/<<PKGBUILDDIR>>=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -std=gnu++11 -fPIC -o CMakeFiles/inspectrum.dir/traceplot.cpp.o -c /<<PKGBUILDDIR>>/traceplot.cpp
| /<<PKGBUILDDIR>>/traceplot.cpp: In member function ‘void TracePlot::plotTrace(QPainter&, const QRect&, float*, size_t, int)’:
| /<<PKGBUILDDIR>>/traceplot.cpp:120:18: error: aggregate ‘QPainterPath path’ has incomplete type and cannot be defined
|   120 |     QPainterPath path;
|       |                  ^~~~
| make[3]: *** [CMakeFiles/inspectrum.dir/build.make:332: CMakeFiles/inspectrum.dir/traceplot.cpp.o] Error 1
| make[3]: Leaving directory '/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu'
| make[2]: *** [CMakeFiles/Makefile2:127: CMakeFiles/inspectrum.dir/all] Error 2
| make[2]: Leaving directory '/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu'
| make[1]: *** [Makefile:163: all] Error 2
| make[1]: Leaving directory '/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu'
| dh_auto_build: error: cd obj-x86_64-linux-gnu && make -j1 "INSTALL=install --strip-program=true" returned exit code 2
| make: *** [debian/rules:3: build] Error 25
| dpkg-buildpackage: error: debian/rules build subprocess returned exit status 2

This seems to be a fairly recent regression induced by one of the
dependencies.

Helmut