Long path names break Windows build (originally: MSVC Generator can break CMake builds)

[LeonMatthesKDAB]

During yesterdays training @narnaud could only build with the Ninja generator, not the MSVC one.

We need to investigate whether we can reproduce this and how to fix it.

@narnaud can you reproduce the error and provide us with the error message please?

[narnaud]

The error log is quite long, here is the beginning:

[build] CUSTOMBUILD : warning : cxx-qt-lib@0.7.1: ToolExecError: command did not execute successfully (status code exit code: 2): "C:/Program Files/Microsoft Visual Studio/2022/Professional/VC/Tools/MSVC/14.43.34808/bin/Hostx64/x64/cl.exe" "-nologo" "-MD" "-Z7" "-Brepro" "-std:c++17" "-I" "C:/Qt/6.8.2/msvc2022_64/include/QtQuickControls2" "-I" "C:/Qt/6.8.2/msvc2022_64/include/QtCore" "-I" "C:/Qt/6.8.2/msvc2022_64/include/QtQml" "-I" "C:/Qt/6.8.2/msvc2022_64/include/QtGui" "-I" "C:/Qt/6.8.2/msvc2022_64/include" "-I" "C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out\\cxx-qt-build\\target\\crates\\cxx-qt-lib\\include" "-I" "C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out\\cxx-qt-build\\target\\crates\\cxx-qt-lib\\include\\cxx-qt-lib-internals" "-I" "C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out/qt-build-utils/moc" "-I" "C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out/qt-build-utils/moc" "-W4" "/Zc:__cplusplus" "/permissive-" "/bigobj" "-DCXX_QT_GUI_FEATURE" "-DCXX_QT_QML_FEATURE" "-DCXX_QT_QUICKCONTROLS_FEATURE" "-FoC:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out\\956f9a0767486f47-qquickstyle.cxxqt.o" "-c" "C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out\\cxx-qt-gen/src/quickcontrols/qquickstyle.cxxqt.cpp"qtimezone.cxx.cpp [C:\dev\rust\training-handout\rust-cxx-qt\sol-imageviewer-cxx-qt\build\ImageFilter\_cargo-build_image_filter.vcxproj]
[build] CUSTOMBUILD : warning : cxx-qt-lib@0.7.1: ToolExecError: command did not execute successfully (status code exit code: 2): "C:/Program Files/Microsoft Visual Studio/2022/Professional/VC/Tools/MSVC/14.43.34808/bin/Hostx64/x64/cl.exe" "-nologo" "-MD" "-Z7" "-Brepro" "-std:c++17" "-I" "C:/Qt/6.8.2/msvc2022_64/include/QtQuickControls2" "-I" "C:/Qt/6.8.2/msvc2022_64/include/QtCore" "-I" "C:/Qt/6.8.2/msvc2022_64/include/QtQml" "-I" "C:/Qt/6.8.2/msvc2022_64/include/QtGui" "-I" "C:/Qt/6.8.2/msvc2022_64/include" "-I" "C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out\\cxx-qt-build\\target\\crates\\cxx-qt-lib\\include" "-I" "C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out\\cxx-qt-build\\target\\crates\\cxx-qt-lib\\include\\cxx-qt-lib-internals" "-I" "C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out/qt-build-utils/moc" "-I" "C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out/qt-build-utils/moc" "-W4" "/Zc:__cplusplus" "/permissive-" "/bigobj" "-DCXX_QT_GUI_FEATURE" "-DCXX_QT_QML_FEATURE" "-DCXX_QT_QUICKCONTROLS_FEATURE" "-FoC:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out\\956f9a0767486f47-qquickstyle.cxx.o" "-c" "C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\\x86_64-pc-windows-msvc\\debug\\build\\cxx-qt-lib-bb82d48ca66ed227\\out\\cxx-qt-gen/src/quickcontrols/qquickstyle.cxx.cpp" [C:\dev\rust\training-handout\rust-cxx-qt\sol-imageviewer-cxx-qt\build\ImageFilter\_cargo-build_image_filter.vcxproj]
[build] CUSTOMBUILD : error : failed to run custom build command for `cxx-qt-lib v0.7.1` [C:\dev\rust\training-handout\rust-cxx-qt\sol-imageviewer-cxx-qt\build\ImageFilter\_cargo-build_image_filter.vcxproj]
[build]   
[build]   Caused by:
[build]     process didn't exit successfully: `C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\debug\build\cxx-qt-lib-0cd847722440e25a\build-script-build` (exit code: 1)
[build]     --- stdout
[build]     cargo::rerun-if-env-changed=QMAKE
[build]     cargo::rerun-if-env-changed=QT_VERSION_MAJOR
[build]     cargo::rerun-if-changed=include/
[build]     cargo::rerun-if-changed=include/common.h
[build]     cargo::rerun-if-changed=include/assertion_utils.h
[build]     cargo::rerun-if-changed=include/core
[build]     cargo::rerun-if-changed=include/core/qanystringview.h
[build]     cargo::rerun-if-changed=include/core/qbytearray.h
[build]     cargo::rerun-if-changed=include/core/qcoreapplication.h
[build]     cargo::rerun-if-changed=include/core/qdate.h
[build]     cargo::rerun-if-changed=include/core/qdatetime.h
...

But I think the interesting part is here:

[build] C:/dev/rust/training-handout/rust-cxx-qt/sol-imageviewer-cxx-qt/build/x64/Debug/cargo/build\x86_64-pc-windows-msvc\debug\build\cxx-qt-lib-bb82d48ca66ed227\out\cxx-qt-gen/src/quickcontrols/qquickstyle.cxx.cpp(3): fatal error C1083: Cannot open include file: 'cxx-qt-lib-internals/src/quickcontrols/qquickstyle.cxxqt.h': No such file or directory [C:\dev\rust\training-handout\rust-cxx-qt\sol-imageviewer-cxx-qt\build\ImageFilter\_cargo-build_image_filter.vcxproj]
[build]     exit code: 0

[narnaud]

In VS Code, to make sure you are using ninja, you need to add a .vscode/settings.json in your project with:

{
    "cmake.generator": "Ninja"
}

Or set it as a user settings and you won't have to think about it anymore.

[LeonMatthesKDAB]

Thank you, so as I remember it, the error is caused by the Cargo build script of cxx-qt-lib.
This is very strange, as those build scripts really don't have much to do with the generator, they're entirely driven by Cargo...

Maybe this has something to do with the file synchronization issues that we have encountered previously on Windows?
But it seems to be reproducable, which points to this not being the case.
Either way, we should see if we can reproduce this in CI.

[klochowicz]

FWIW, I've just run into this issue today, and can reliably reproduce it on our (internal) GitLab CI (cxx-qt 0.7.1, msvc generator).

Will try to switch to ninja....