Long paths are not supported

[qr243vbi]

2025-12-01T11:37:15.6907180Z Package: qtdeclarative:arm64-windows@6.9.1
2025-12-01T11:37:15.6907403Z
2025-12-01T11:37:15.6907482Z Host Environment
2025-12-01T11:37:15.6907604Z
2025-12-01T11:37:15.6907696Z - Host: arm64-windows
2025-12-01T11:37:15.6911542Z - Compiler: MSVC 19.44.35217.0
2025-12-01T11:37:15.6911812Z - CMake Version: 3.31.8
2025-12-01T11:37:15.6912099Z - vcpkg-tool version: 2025-10-16-71538f2694db93da4668782d094768ba74c45991
2025-12-01T11:37:15.7366592Z vcpkg-scripts version: 74e6536 2025-10-17 (6 weeks ago)
2025-12-01T11:37:15.7367094Z
2025-12-01T11:37:15.7367386Z To Reproduce
2025-12-01T11:37:15.7367774Z
2025-12-01T11:37:15.7368031Z vcpkg install qtgrpc qtcharts qtdeclarative qtbase qttools
2025-12-01T11:37:15.7368347Z
2025-12-01T11:37:15.7368563Z Failure logs
2025-12-01T11:37:15.7368948Z
2025-12-01T11:37:15.7369024Z ```
2025-12-01T11:37:15.7369329Z CMake Warning at scripts/cmake/vcpkg_buildpath_length_warning.cmake:4 (message):
2025-12-01T11:37:15.7370215Z qtdeclarative's buildsystem uses very long paths and may fail on your
2025-12-01T11:37:15.7370584Z system.
2025-12-01T11:37:15.7370678Z
2025-12-01T11:37:15.7370871Z We recommend moving vcpkg to a short path such as 'C:\src\vcpkg' or using
2025-12-01T11:37:15.7375657Z the subst command.
2025-12-01T11:37:15.7375914Z Call Stack (most recent call first):
2025-12-01T11:37:15.7377128Z ports/qtdeclarative/portfile.cmake:4 (vcpkg_buildpath_length_warning)
2025-12-01T11:37:15.7378817Z scripts/ports.cmake:206 (include)
2025-12-01T11:37:15.7379068Z
2025-12-01T11:37:15.7379073Z
2025-12-01T11:37:15.7379677Z Downloading qtdeclarative-everywhere-src-6.9.1.tar.xz, trying https://download.qt.io/archive/qt/6.9/6.9.1/submodules/qtdeclarative-everywhere-src-6.9.1.tar.xz
2025-12-01T11:37:15.7380694Z Successfully downloaded qtdeclarative-everywhere-src-6.9.1.tar.xz
2025-12-01T11:37:15.7381413Z -- Extracting source C:/a/qt_windows_arm/qt_windows_arm/vcpkg/downloads/qtdeclarative-everywhere-src-6.9.1.tar.xz
2025-12-01T11:37:15.7382303Z -- Using source at C:/a/qt_windows_arm/qt_windows_arm/vcpkg/buildtrees/qtdeclarative/src/here-src-6-64fcc28293.clean
2025-12-01T11:37:15.7382997Z -- Configuring arm64-windows
2025-12-01T11:37:15.7383316Z -- Building arm64-windows-dbg
2025-12-01T11:37:15.7383937Z CMake Error at scripts/cmake/vcpkg_execute_build_process.cmake:134 (message):
2025-12-01T11:37:15.7384636Z Command failed: "C:/Program Files/CMake/bin/cmake.exe" --build . --config Debug --target install -- -v -j5
2025-12-01T11:37:15.7385291Z Working Directory: C:/a/qt_windows_arm/qt_windows_arm/vcpkg/buildtrees/qtdeclarative/arm64-windows-dbg
2025-12-01T11:37:15.7385945Z See logs for more information:
2025-12-01T11:37:15.7386527Z C:\a\qt_windows_arm\qt_windows_arm\vcpkg\buildtrees\qtdeclarative\install-arm64-windows-dbg-out.log
2025-12-01T11:37:15.7390613Z
2025-12-01T11:37:15.7390774Z Call Stack (most recent call first):
2025-12-01T11:37:15.7391663Z installed/arm64-windows/share/vcpkg-cmake/vcpkg_cmake_build.cmake:74 (vcpkg_execute_build_process)
2025-12-01T11:37:15.7392307Z installed/arm64-windows/share/vcpkg-cmake/vcpkg_cmake_install.cmake:16 (vcpkg_cmake_build)
2025-12-01T11:37:15.7392884Z installed/arm64-windows/share/qtbase/qt_install_submodule.cmake:376 (vcpkg_cmake_install)
2025-12-01T11:37:15.7393652Z ports/qtdeclarative/portfile.cmake:30 (qt_install_submodule)
2025-12-01T11:37:15.7394013Z scripts/ports.cmake:206 (include)

[qr243vbi]

I believe there is a solution to this issue. Please add a custom_dir option to set a custom directory for vcpkg. When I changed the repository name from qt_windows_arm to a, the error no longer occurred.

[johnwason]

Have you tried using the --x-buildtrees-root= option with extra-args? This should allow you to move the build directory out of the github workspace root.