如何在配置文件中设置vcpkg的--x-buildtrees-root选项解决路径过长问题

方法1：在CMakePresets.json的缓存变量中配置 #

直接在你的CMake构建预设里添加VCPKG_INSTALL_OPTIONS缓存变量，指定短路径参数即可：

打开项目根目录下的CMakePresets.json，找到对应的配置预设（比如Debug/Release架构预设），添加如下配置：

{
  "version": 3,
  "configurePresets": [
    {
      "name": "windows-x64-debug",
      "displayName": "Windows x64 Debug",
      "generator": "Visual Studio 17 2022",
      "architecture": "x64",
      "cacheVariables": {
        "CMAKE_TOOLCHAIN_FILE": "$env{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake",
        // 替换为你的短路径，比如C盘根目录下的短名称文件夹
        "VCPKG_INSTALL_OPTIONS": "--x-buildtrees-root=C:/vcpkg-build"
      }
    }
  ]
}

方法2：通过环境变量配置（可选） #

也可以在预设的environment字段中设置VCPKG_INSTALL_OPTIONS环境变量，效果与上述方法一致：

{
  "version": 3,
  "configurePresets": [
    {
      "name": "windows-x64-debug",
      "displayName": "Windows x64 Debug",
      "generator": "Visual Studio 17 2022",
      "architecture": "x64",
      "cacheVariables": {
        "CMAKE_TOOLCHAIN_FILE": "$env{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake"
      },
      "environment": {
        "VCPKG_INSTALL_OPTIONS": "--x-buildtrees-root=C:/vcpkg-build"
      }
    }
  ]
}

优化：使用预设继承减少重复配置 #

如果有多个构建预设（比如Debug/Release、不同架构），可以创建一个基础预设，让其他预设继承它，避免重复编写相同配置：

{
  "version": 3,
  "configurePresets": [
    {
      "name": "windows-base",
      "hidden": true,
      "generator": "Visual Studio 17 2022",
      "cacheVariables": {
        "CMAKE_TOOLCHAIN_FILE": "$env{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake",
        "VCPKG_INSTALL_OPTIONS": "--x-buildtrees-root=C:/vcpkg-build"
      }
    },
    {
      "name": "windows-x64-debug",
      "displayName": "Windows x64 Debug",
      "architecture": "x64",
      "inherits": "windows-base",
      "cacheVariables": {
        "CMAKE_BUILD_TYPE": "Debug"
      }
    },
    {
      "name": "windows-x64-release",
      "displayName": "Windows x64 Release",
      "architecture": "x64",
      "inherits": "windows-base",
      "cacheVariables": {
        "CMAKE_BUILD_TYPE": "Release"
      }
    }
  ]
}

注意事项 #

• 替换C:/vcpkg-build为你自己的短路径，确保路径长度足够短以解决QtWebEngine的路径过长问题
• 建议手动创建该路径对应的文件夹，避免vcpkg自动创建时出现权限问题
• 配置完成后，重新在Visual Studio中加载CMake项目，后续构建依赖时vcpkg会自动带上该参数

内容的提问来源于stack exchange，提问作者Jepessen