"The command line is too long" when building the app

  • I'm trying to build an example "coffee" using Qt 6.2.2. I installed emsdk version 2.0.13 and configured both Qt creator using this tutorial https://doc.qt.io/qtcreator/creator-setup-webassembly.html and environment variables to make it possible to use command line. I tried to build the project using these two ways and I was always getting an error:

    The command line is too long.
    mingw32-make: *** [Makefile:87: .\coffee.js] Error 1
    20:23:22: The process "C:\Qt\Tools\mingw900_64\bin\mingw32-make.exe" exited with code 2.
    Error while building/deploying project coffee (kit: Qt 6.2.2 WebAssembly)
    When executing step "Make"

    The "Make" step consists out of two commands:

    1. qmake.bat coffee.pro
    2. mingw32-make.exe -j4 in C:\Qt\Examples\Qt-6.2.2\demos\build-coffee-Qt_6_2_2_WebAssembly-Debug

  • I managed to compile examples, but only when using Qt version 5.15.2 and emscripten 1.39.7

  • https://bugreports.qt.io/browse/QTBUG-84392

    With Qt 6.2, you can use qt-cmake to build examples, which does not have this issue.