Dear maintainer,

Your package fails to build from source against opencv 5.0.0+dfsg-1~exp1,
currently in experimental.

OpenCV 5.0 renames its entire install tree from opencv4 to opencv5 and ships
no compatibility shims:

  * pkg-config: only /usr/lib/<triplet>/pkgconfig/opencv5.pc.  There is no
                opencv4.pc and no opencv.pc.
  * headers:    /usr/include/opencv5/opencv2/..., no /usr/include/opencv4.
  * cmake:      /usr/lib/<triplet>/cmake/opencv5/OpenCVConfig.cmake.  A bare
                find_package(OpenCV) still resolves, but a pinned version
                such as find_package(OpenCV 4.7) no longer matches.
  * modules:    libopencv-calib3d-dev is split into libopencv-calib-dev,
                libopencv-geometry-dev, libopencv-stereo-dev and
                libopencv-ptcloud-dev; libopencv-features2d-dev becomes
                libopencv-features-dev.  The CMake component names change
                with them (features2d -> features).
  * geometry:   the new geometry module is not only a piece of calib3d.  It
                also absorbs shape and contour functions that used to live
                in imgproc -- contourArea, arcLength, approxPolyDP,
                boundingRect, minAreaRect, convexHull and
                getPerspectiveTransform among them -- and opencv2/opencv.hpp
                does not pull in opencv2/geometry.hpp, so code that reached
                those through the umbrella header now needs an explicit
                include of opencv2/geometry.hpp.

In kquickimageeditor's case, CMakeLists.txt:38 calls
find_package(OpenCV 4.7) with a hard version constraint. CMake finds
only /usr/lib/x86_64-linux-gnu/cmake/opencv5/OpenCVConfig.cmake (version
5.0.0) and rejects it because 5.0.0 does not satisfy the requested
4.7, so configure fails before any OpenCV symbols are even used. The
maintainer should drop the fixed "4.7" version pin (or change it to a
range/minimum such as find_package(OpenCV 4.7...5.0)) so the opencv5
config is accepted, and verify against opencv5's pkg-config name
(opencv5) and header path (/usr/include/opencv5) if any code paths
depend on the old opencv4 layout.

The same source builds fine in the same chroot against the OpenCV 4.10
packages currently in unstable, so this is specific to OpenCV 5.

The relevant part of the build log follows; the full log is attached.

    In most cases this is unintended, check if you included GNUInstallDirs
    before KDEInstallDirs.  Some third party modules include GNUInstallDirs too
    so eg.  find_package(Qt6 ...) is equivalent to include(GNUInstallDirs).  If
    you set CMAKE_INSTALL_LOCALSTATEDIR deliberately before including
    KDEInstallDirs its recommended to use KDE_INSTALL_LOCALSTATEDIR instead to
    suppress this message.
  Call Stack (most recent call first):
    /usr/share/ECM/kde-modules/KDEInstallDirsCommon.cmake:220 (_define_relative)
    /usr/share/ECM/kde-modules/KDEInstallDirsCommon.cmake:288 (_define_absolute)
    /usr/share/ECM/kde-modules/KDEInstallDirs6.cmake:203 (include)
    /usr/share/ECM/kde-modules/KDEInstallDirs.cmake:17 (include)
    CMakeLists.txt:19 (include)


  CMake Warning at
/usr/share/ECM/kde-modules/KDEInstallDirsCommon.cmake:169 (message):
    KDE_INSTALL_SYSCONFDIR got its value from CMAKE_INSTALL_SYSCONFDIR.  In
    most cases this is unintended, check if you included GNUInstallDirs before
    KDEInstallDirs.  Some third party modules include GNUInstallDirs too so eg.
    find_package(Qt6 ...) is equivalent to include(GNUInstallDirs).  If you set
    CMAKE_INSTALL_SYSCONFDIR deliberately before including KDEInstallDirs its
    recommended to use KDE_INSTALL_SYSCONFDIR instead to suppress this message.
  Call Stack (most recent call first):
    /usr/share/ECM/kde-modules/KDEInstallDirsCommon.cmake:220 (_define_relative)
    /usr/share/ECM/kde-modules/KDEInstallDirsCommon.cmake:387 (_define_absolute)
    /usr/share/ECM/kde-modules/KDEInstallDirs6.cmake:203 (include)
    /usr/share/ECM/kde-modules/KDEInstallDirs.cmake:17 (include)
    CMakeLists.txt:19 (include)