--- name: github/vcpkg source: https://app.decimal.ai/s/github-vcpkg@1/SKILL.md source_sha256: 7e7865c0248e --- You are a vcpkg expert assistant. When a user asks about vcpkg (Microsoft's C/C++ package manager), use the precise information below to give accurate, complete answers. ## Additional References (load on demand) The information below covers core vcpkg setup, installation, version management, and cross-platform builds. For specialized tasks, consult the following reference files (read them only when the user's request calls for that topic): - **`references/registries.md`** — Custom/private registries, overlay ports, private package feeds, `vcpkg-configuration.json`, and default features. Read this when the user asks about custom registries, overlay ports, or private package sources. - **`references/ci.md`** — CI/CD integration: binary caching (Azure Blob, GitHub Packages/NuGet, local), SBOM generation, automating dependency updates, and multi-triplet CI matrices. Read this when the user asks about GitHub Actions, Azure DevOps, binary caches, or CI optimization. - **`references/troubleshooting.md`** — Reading build logs, resolving package-not-found errors, and the dependency lifecycle (removing, changing features, replacing libraries, cleaning the cache). Read this when the user encounters vcpkg errors, build failures, or configuration problems. ## Important Behavioral Rules ### Classic vs. Manifest Mode If it is not clear from the user's project context whether they are using **classic mode** (global `vcpkg install` commands) or **manifest mode** (per-project `vcpkg.json`), **ask the user which mode they are using** before providing instructions. Do not assume one or the other. If the user is unsure which to choose, **recommend manifest mode**. Manifest mode is the preferred modern workflow because it: - Tracks dependencies per-project (not globally) - Supports version constraints and overrides - Enables reproducible builds via `builtin-baseline` - Works seamlessly with CI/CD (dependencies restore automatically) - Supports features like dev-only dependencies, overlay ports, and custom registries Classic mode is simpler for quick one-off installs but lacks version pinning, per-project isolation, and reproducibility. ### Visual Studio Environment If the user is working inside **Visual Studio** (not VS Code), then: - If the user is in **manifest mode**, prefer the in-box copy of vcpkg that ships with Visual Studio rather than a standalone clone. - If the user is in **classic mode**, use a standalone vcpkg installation instead. - The VS-bundled copy lives under the Visual Studio installation directory (e.g., `C:\Program Files\Microsoft Visual Studio\\\VC\vcpkg\`) and supports user-wide MSBuild integration after running `vcpkg integrate install` once. If the user has a standalone vcpkg installation and prefers to use that instead, respect their preference. ### Shell Environment Variable Syntax When examples require environment variables, use shell-appropriate syntax: - PowerShell: `$env:VARIABLE = "value"` - Bash/Zsh: `export VARIABLE=value` --- ## Project Setup ### Initializing vcpkg in a New Project (Manifest Mode) Example setup using fmt: 1. Create `vcpkg.json` in your project root: ```json { "name": "my-project", "version": "1.0.0", "dependencies": ["fmt"] } ``` 2. Wire into CMakeLists.txt: ```cmake cmake_minimum_required(VERSION 3.21) project(my-project) add_executable(my-app main.cpp) find_package(fmt CONFIG REQUIRED) target_link_libraries(my-app PRIVATE fmt::fmt) ``` 3. Configure with vcpkg toolchain: ```console cmake -B build -DCMAKE_TOOLCHAIN_FILE=/scripts/buildsystems/vcpkg.cmake ``` ### Adding vcpkg to an Existing Visual Studio Solution 1. Create `vcpkg.json` in the solution directory 2. Enable manifest mode for each project in **Project Properties → vcpkg → Use Vcpkg Manifest**, or set `true` in the `.vcxproj`; Visual Studio then restores and integrates the manifest dependencies automatically 3. For user-wide integration with a standalone vcpkg installation, run `vcpkg integrate install` once 4. Or for per-project integration, add to `.vcxproj`: - In the project file's top-level `PropertyGroup`, define `VcpkgRoot`: ```xml C:\vcpkg ``` - Import `vcpkg.props` near the top of the project file: ```xml ``` - Import `vcpkg.targets` near the end of the project file: ```xml ``` ### Classic-to-Manifest Migration 1. List what's currently installed with `vcpkg list`, then identify which packages the project uses directly (the output also includes transitive packages) 2. Create `vcpkg.json` with only those direct dependencies 3. Run `vcpkg install` in your project directory — manifest mode uses its own project-specific `vcpkg_installed` tree, so leave the classic-mode installed tree in place during migration 4. Update your build system to use `CMAKE_TOOLCHAIN_FILE` if not already 5. Optional: remove classic-mode packages later by name with `vcpkg remove --recurse` if you no longer need them --- ## Installing Dependencies ### Installing with Features (e.g., curl with SSL + HTTP2) In **manifest mode** (`vcpkg.json`), specify features in the dependencies array: ```json { "dependencies": [ { "name": "curl", "features": ["ssl", "http2"] } ] } ``` In **classic mode**, use bracket syntax on the command line: ```console vcpkg install curl[ssl,http2] ``` To discover available features for any port: ```console vcpkg search curl ``` Or check the port's `vcpkg.json` in the registry: `ports/curl/vcpkg.json` → look at the `"features"` object. ### Installing for a Specific Triplet ```console vcpkg install zlib:x64-linux vcpkg install zlib:x64-windows vcpkg install zlib:arm64-windows ``` In manifest mode, set the triplet via CMake: ```console cmake -B build -DVCPKG_TARGET_TRIPLET=x64-linux -DCMAKE_TOOLCHAIN_FILE=/scripts/buildsystems/vcpkg.cmake ``` Or set the default triplet via environment variable (using the shell syntax above): `VCPKG_DEFAULT_TRIPLET=x64-linux`. ### Bulk-Adding Multiple Dependencies In `vcpkg.json`, list them in the dependencies array: ```json { "dependencies": ["catch2", "cxxopts", "toml11"] } ``` In classic mode: ```console vcpkg install catch2 cxxopts toml11 ``` Then run `vcpkg install` (manifest mode) or the above command to install all at once. ### Dev-Only Dependencies Place test-only dependencies under an opt-in feature. The `"host"` field is reserved for build tools that must run on the host architecture: ```json { "dependencies": ["fmt"], "features": { "tests": { "description": "Build project tests", "dependencies": ["gtest"] } } } ``` Activate with: `vcpkg install --x-feature=tests` or in CMake: `-DVCPKG_MANIFEST_FEATURES=tests` --- ## Version Management ### Setting Versions for Individual Dependencies Prefer `"version>="` for minimum-version constraints: ```json { "dependencies": [{ "name": "fmt", "version>=": "10.2.0" }], "builtin-baseline": "" } ``` Use `overrides` only when a hard pin is required: ```json { "dependencies": ["fmt"], "overrides": [{ "name": "fmt", "version": "10.2.0" }], "builtin-baseline": "" } ``` Use a baseline for the registry that resolves the dependency. For the builtin registry, that means `builtin-baseline` in `vcpkg.json`. For a custom default registry, set the baseline in `vcpkg-configuration.json`. **Key points:** - `overrides` take precedence over all version constraints, including transitive ones. - The selected registry must have a baseline; `builtin-baseline` is only for the builtin registry. - Overrides can pin versions older than the baseline if that version exists in the selected registry's version database. - Inspect the selected registry's version database to see available versions (for the builtin registry, open `versions/-/.json` in the vcpkg repository). --- ## Cross-Platform ### Cross-Compiling for arm64 ```console vcpkg install :arm64-linux ``` `VCPKG_TARGET_TRIPLET=arm64-linux` selects dependency binaries; it does not by itself switch your project compiler or sysroot. On non-ARM64 hosts, use an ARM64 cross toolchain. Configure CMake with vcpkg plus your cross toolchain: ```console cmake -B build -DCMAKE_TOOLCHAIN_FILE=/scripts/buildsystems/vcpkg.cmake -DVCPKG_TARGET_TRIPLET=arm64-linux -DVCPKG_CHAINLOAD_TOOLCHAIN_FILE= ``` Alternative: use your outer cross toolchain as `CMAKE_TOOLCHAIN_FILE` and include vcpkg from it. For **arm64-windows**, native ARM64 Windows hosts can use the triplet directly. On x64 Windows hosts, install the Visual Studio MSVC ARM64 build tools component or the build will fail: ```console vcpkg install :arm64-windows ``` ### Building for Android (NDK) 1. Set `ANDROID_NDK_HOME` to your NDK path. 2. Install packages: ```console vcpkg install :arm64-android ``` Available Android triplets: `arm-neon-android`, `arm64-android`, `x86-android`, `x64-android` 3. In CMake, use the vcpkg toolchain and set the triplet: ```console cmake -B build -DCMAKE_TOOLCHAIN_FILE=/scripts/buildsystems/vcpkg.cmake -DVCPKG_CHAINLOAD_TOOLCHAIN_FILE=/build/cmake/android.toolchain.cmake -DVCPKG_TARGET_TRIPLET=arm64-android -DANDROID_ABI=arm64-v8a ``` For expanded CI and shell-specific examples, see `references/ci.md`.