pct FTBFS against vtk 9.6
(currently available in experimental)
The problem is linking the executables
e.g.
[ 38%] Linking CXX executable ../bin/pcl_viewer
cd /build/vtk-dep/pcl-1.15.1+dfsg/obj-x86_64-linux-gnu/tools && /usr/bin/cmake -E cmake_link_script CMakeFiles/pcl_viewer.dir/link.txt --verbose=1
/usr/bin/g++ -g -O2 -ffile-prefix-map=/build/vtk-dep/pcl-1.15.1+dfsg=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -g1 -Wdate-time -D_FORTIFY_SOURCE=2 -fopenmp -Wl,-z,relro -Wl,-z,now -L/usr/lib/x86_64-linux-gnu/fortran/gnu -Wl,--dependency-file=CMakeFiles/pcl_viewer.dir/link.d CMakeFiles/pcl_viewer.dir/pcd_viewer.cpp.o -o ../bin/pcl_viewer ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1 ../lib/x86_64-linux-gnu/libpcl_io.so.1.15.1 /usr/lib/x86_64-linux-gnu/libboost_iostreams.so.1.90.0 /usr/lib/x86_64-linux-gnu/libboost_random.so.1.90.0 /usr/lib/x86_64-linux-gnu/libboost_regex.so.1.90.0 ../lib/x86_64-linux-gnu/libpcl_io_ply.so.1.15.1 /usr/lib/x86_64-linux-gnu/libboost_filesystem.so.1.90.0 /usr/lib/x86_64-linux-gnu/libboost_atomic.so.1.90.0 /usr/lib/x86_64-linux-gnu/libvtkIOGeometry-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libpng.so /usr/lib/x86_64-linux-gnu/libz.so /usr/lib/x86_64-linux-gnu/libusb-1.0.so /usr/lib/x86_64-linux-gnu/libOpenNI2.so /usr/lib/libOpenNI.so /usr/lib/x86_64-linux-gnu/libpcap.so ../lib/x86_64-linux-gnu/libpcl_search.so.1.15.1 ../lib/x86_64-linux-gnu/libpcl_kdtree.so.1.15.1 ../lib/x86_64-linux-gnu/libpcl_octree.so.1.15.1 /usr/lib/x86_64-linux-gnu/libflann_cpp.so.1.9.2 -Wl,-whole-archive /usr/lib/x86_64-linux-gnu/libflann_cpp_s.a /usr/lib/x86_64-linux-gnu/liblz4.so /usr/lib/x86_64-linux-gnu/libxxhash.so -Wl,-no-whole-archive /usr/lib/x86_64-linux-gnu/libvtkIOPLY-9.6.so.9.6 ../lib/x86_64-linux-gnu/libpcl_common.so.1.15.1 /usr/lib/gcc/x86_64-linux-gnu/15/libgomp.so /usr/lib/x86_64-linux-gnu/libpthread.a -lm -latomic /usr/lib/x86_64-linux-gnu/libOpenGL.so /usr/lib/x86_64-linux-gnu/libGLX.so /usr/lib/x86_64-linux-gnu/libGLU.so /usr/lib/x86_64-linux-gnu/libvtkChartsCore-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkInteractionImage-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkRenderingLOD-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkViewsContext2D-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkViewsCore-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkRenderingContextOpenGL2-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkGUISupportQt-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkRenderingOpenGL2-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkRenderingHyperTreeGrid-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkRenderingUI-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkglad-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkx11-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkInteractionWidgets-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkFiltersModeling-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkInteractionStyle-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkFiltersExtraction-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkIOLegacy-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkIOCellGrid-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkFiltersCellGrid-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkRenderingAnnotation-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkRenderingContext2D-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkRenderingFreeType-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libfreetype.so /usr/lib/x86_64-linux-gnu/libvtkImagingSources-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkIOImage-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkIOCore-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkImagingCore-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkRenderingCore-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkCommonColor-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkFiltersSources-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkFiltersGeneral-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkFiltersGeometry-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkFiltersCore-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkCommonComputationalGeometry-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkCommonExecutionModel-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkCommonDataModel-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkCommonMisc-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkCommonTransforms-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkCommonMath-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libvtkkissfft-9.6.so.9.6 /usr/lib/x86_64-linux-gnu/libQt6OpenGLWidgets.so.6.10.2 /us/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XKeysymToString'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XOpenDisplay'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XFlush'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XSync'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XQueryPointer'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XFree'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XNextEvent'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XSetWMProtocols'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XCheckTypedWindowEvent'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XTranslateCoordinates'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XLookupKeysym'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XSetInputFocus'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XGetWindowAttributes'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XChangeProperty'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XInternAtom'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XGetWindowProperty'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XSendEvent'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XSelectInput'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XConvertSelection'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XPending'
/usr/bin/x86_64-linux-gnu-ld.bfd: ../lib/x86_64-linux-gnu/libpcl_visualization.so.1.15.1: undefined reference to `XCloseDisplay'
collect2: error: ld returned 1 exit status
These are X11 symbols, not VTK symbols.
Is pcl missing configuration for some -l links to X libraries?