Important: Please read the Qt Code of Conduct -

Problems installing opencv for Qt (chmod not found)

  • Hi!
    I am trying to install opencv on my windows 10 notebook for Qt. I followed this guide:
    I installed Cmake successfully, Qt is already (5.10).
    But I have trouble running the mingw in the opencv-build folder.

    modules\core\CMakeFiles\pch_Generate_opencv_core.dir\build.make:62: recipe for target 'modules/core/precomp.hpp.gch/opencv_core_Release.gch' failed
    mingw32-make[2]: *** [modules/core/precomp.hpp.gch/opencv_core_Release.gch] Error 1
    CMakeFiles\Makefile2:1509: recipe for target 'modules/core/CMakeFiles/pch_Generate_opencv_core.dir/all' failed
    mingw32-make[1]: *** [modules/core/CMakeFiles/pch_Generate_opencv_core.dir/all] Error 2
    Makefile:161: recipe for target 'all' failed
    mingw32-make: *** [all] Error 2

    Then it tells me, command 'chmod' could not be found. I don't really understand, isn't chmod only a unix command?
    Thanks for help!

  • Lifetime Qt Champion


    AFAIK, yes it's a Unix command. This is intriguing ?

    What command line are you using ?

  • @sgaist said in Problems installing opencv for Qt (chmod not found):

    What command line are you using ?



  • Lifetime Qt Champion

    So Windows own cmd ?

  • @sgaist

    The problem has shifted now (which doesn't mean, the chmod error isn't completely weird). I disabled ENABLE_PRECOMPILED_HEADERS in CMake, then regenerated the opencv-build directory via CMake once again and tried again. Now, I don't get the error again, but the make process keeps slowing down until it takes hours to complete one %. Canceling and restarting the make results in starting again at a lower percentage and still taking very long time to build one thing. It's just getting weirder... So I don't think, the problem is specific to this chmod thing but something fundamental is not working correctly although I followed the linked tutorial. Which makes it quite hard to isolate the source of the issue.

  • @niagarer not that I've used myself, but is there any wrong with installing the pre-built binaries provided by OpenCV project?

Log in to reply