Bug#1142180: FTBFS: vtkVizInteractorStyle.cpp:99:5: error: ‘cout’ was not declared in this scope

[Drew Parsons]

Source: opencv
Version: 4.10.0+dfsg-7
Severity: serious
Tags: ftbfs

opencv currently FTBFS,
see https://buildd.debian.org/status/fetch.php?pkg=opencv&arch=amd64&ver=4.10.0%2Bdfsg-7%2Bb3&stamp=1784188231&raw=0

[552/1223] /usr/bin/x86_64-linux-gnu-g++ -DCVAPI_EXPORTS -DFMT_SHARED -DGLAD_API_CALL_EXPORT -DSCN_DISABLE_FAST_FLOAT=0 -DSCN_DISABLE_REGEX=0 -DSCN_REGEX_BACKEND=0 -D_USE_MATH_DEFINES -D__OPENCV_BUILD=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Dkiss_fft_scalar=double -DvtkRenderingCore_AUTOINIT_INCLUDE=\"/build/reproducible-path/opencv-4.10.0+dfsg/obj-x86_64-linux-gnu/CMakeFiles/vtkModuleAutoInit_be7301261a49b13d6a9b1d9e110eacd8.h\" -I/build/reproducible-path/opencv-4.10.0+dfsg/obj-x86_64-linux-gnu -I/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/include -I/build/reproducible-path/opencv-4.10.0+dfsg/obj-x86_64-linux-gnu/modules/viz -I/build/reproducible-path/opencv-4.10.0+dfsg/modules/core/include -isystem /usr/include/gdal -isystem /usr/include/eigen3 -isystem /usr/include/vtk-9.6 -isystem /usr/include/vtk-9.6/vtkfmt -isystem /usr/include/vtk-9.6/vtkscn/include -isystem /usr/include/vtk-9.6/vtkscn -isystem /usr/include/vtk-9.6/token -isystem /usr/include/vtk-9.6/vtkkissfft -isystem /usr/include/freetype2 -isystem /usr/include/jsoncpp -isystem /usr/include/vtk-9.6/vtkglad -g -O2 -ffile-prefix-map=/build/reproducible-path/opencv-4.10.0+dfsg=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -Wdate-time -D_FORTIFY_SOURCE=2   -fsigned-char -W -Wall -Wreturn-type -Wnon-virtual-dtor -Waddress -Wsequence-point -Wformat -Wformat-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wuninitialized -Wno-delete-non-virtual-dtor -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections  -msse -msse2 -fvisibility=hidden -fvisibility-inlines-hidden -Wno-suggest-override -g -O2 -ffile-prefix-map=/build/reproducible-path/opencv-4.10.0+dfsg=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection  -DNDEBUG -std=c++17 -fPIC -MD -MT modules/viz/CMakeFiles/opencv_viz.dir/src/vtk/vtkVizInteractorStyle.cpp.o -MF modules/viz/CMakeFiles/opencv_viz.dir/src/vtk/vtkVizInteractorStyle.cpp.o.d -o modules/viz/CMakeFiles/opencv_viz.dir/src/vtk/vtkVizInteractorStyle.cpp.o -c /build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp
FAILED: [code=1] modules/viz/CMakeFiles/opencv_viz.dir/src/vtk/vtkVizInteractorStyle.cpp.o 
/usr/bin/x86_64-linux-gnu-g++ -DCVAPI_EXPORTS -DFMT_SHARED -DGLAD_API_CALL_EXPORT -DSCN_DISABLE_FAST_FLOAT=0 -DSCN_DISABLE_REGEX=0 -DSCN_REGEX_BACKEND=0 -D_USE_MATH_DEFINES -D__OPENCV_BUILD=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Dkiss_fft_scalar=double -DvtkRenderingCore_AUTOINIT_INCLUDE=\"/build/reproducible-path/opencv-4.10.0+dfsg/obj-x86_64-linux-gnu/CMakeFiles/vtkModuleAutoInit_be7301261a49b13d6a9b1d9e110eacd8.h\" -I/build/reproducible-path/opencv-4.10.0+dfsg/obj-x86_64-linux-gnu -I/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/include -I/build/reproducible-path/opencv-4.10.0+dfsg/obj-x86_64-linux-gnu/modules/viz -I/build/reproducible-path/opencv-4.10.0+dfsg/modules/core/include -isystem /usr/include/gdal -isystem /usr/include/eigen3 -isystem /usr/include/vtk-9.6 -isystem /usr/include/vtk-9.6/vtkfmt -isystem /usr/include/vtk-9.6/vtkscn/include -isystem /usr/include/vtk-9.6/vtkscn -isystem /usr/include/vtk-9.6/token -isystem /usr/include/vtk-9.6/vtkkissfft -isystem /usr/include/freetype2 -isystem /usr/include/jsoncpp -isystem /usr/include/vtk-9.6/vtkglad -g -O2 -ffile-prefix-map=/build/reproducible-path/opencv-4.10.0+dfsg=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -Wdate-time -D_FORTIFY_SOURCE=2   -fsigned-char -W -Wall -Wreturn-type -Wnon-virtual-dtor -Waddress -Wsequence-point -Wformat -Wformat-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wuninitialized -Wno-delete-non-virtual-dtor -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections  -msse -msse2 -fvisibility=hidden -fvisibility-inlines-hidden -Wno-suggest-override -g -O2 -ffile-prefix-map=/build/reproducible-path/opencv-4.10.0+dfsg=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection  -DNDEBUG -std=c++17 -fPIC -MD -MT modules/viz/CMakeFiles/opencv_viz.dir/src/vtk/vtkVizInteractorStyle.cpp.o -MF modules/viz/CMakeFiles/opencv_viz.dir/src/vtk/vtkVizInteractorStyle.cpp.o.d -o modules/viz/CMakeFiles/opencv_viz.dir/src/vtk/vtkVizInteractorStyle.cpp.o -c /build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp: In member function ‘void cv::viz::vtkVizInteractorStyle::saveScreenshot(const cv::String&)’:
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp:99:5: error: ‘cout’ was not declared in this scope
   99 |     cout << "Screenshot successfully captured (" << file.c_str() << ")" << endl;
      |     ^~~~
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp: In member function ‘void cv::viz::vtkVizInteractorStyle::exportScene(const cv::String&)’:
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp:118:23: warning: ‘void vtkExporter::SetInput(vtkRenderWindow*)’ is deprecated: Please use SetRenderWindow instead [-Wdeprecated-declarations]
  118 |     exporter->SetInput(Interactor->GetRenderWindow());
      |     ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/vtk-9.6/vtkOBJExporter.h:19,
                 from /build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/../precomp.hpp:126,
                 from /build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp:46:
/usr/include/vtk-9.6/vtkExporter.h:86:8: note: declared here
   86 |   void SetInput(vtkRenderWindow* renWin) { this->SetRenderWindow(renWin); }
      |        ^~~~~~~~
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp:121:5: error: ‘cout’ was not declared in this scope
  121 |     cout << "Scene successfully exported (" << file.c_str() << ")" << endl;
      |     ^~~~
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp: In member function ‘void cv::viz::vtkVizInteractorStyle::printCameraParams()’:
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp:176:10: error: ‘cout’ is not a member of ‘std’
  176 |     std::cout << data.c_str() << std::endl;
      |          ^~~~
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp:47:1: note: ‘std::cout’ is defined in header ‘<iostream>’; this is probably fixable by adding ‘#include <iostream>’
   46 | #include "../precomp.hpp"
  +++ |+#include <iostream>
   47 | 
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp: In member function ‘void cv::viz::vtkVizInteractorStyle::printHelp()’:
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp:270:10: error: ‘cout’ is not a member of ‘std’
  270 |     std::cout << "| Help:\n"
      |          ^~~~
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp:270:10: note: ‘std::cout’ is defined in header ‘<iostream>’; this is probably fixable by adding ‘#include <iostream>’
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp: In member function ‘virtual void cv::viz::vtkVizInteractorStyle::OnKeyDown()’:
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp:398:14: error: ‘cout’ is not a member of ‘std’
  398 |         std::cout << (FlyMode ? "Fly mode: on" : "Fly mode: off") << std::endl;
      |              ^~~~
/build/reproducible-path/opencv-4.10.0+dfsg/contrib/modules/viz/src/vtk/vtkVizInteractorStyle.cpp:398:14: note: ‘std::cout’ is defined in header ‘<iostream>’; this is probably fixable by adding ‘#include <iostream>’


The build error appears to have been triggered by the transition to vtk 9.6,
but the error itself is in opencv's modules files,
trying to access std::cout without declaring #include <iostream>

There is a new upstream release, does it fix the issue?