CMake package config for installed packges not found in manifest mode

[acki-m]

I have following vcpkg.json created:

{
  "name": "cpp-project",
  "version": "1.0.0",
  "description": "C++ project with OpenCASCADE (minimal) and uWebSockets",
  "dependencies": [
    {
      "name": "opencascade",
      "version>=": "7.9.1",
      "default-features": false,
      "features": ["rapidjson"]
    },
    {
      "name": "uwebsockets",
      "version>=": "20.74.0",
      "default-features": true,
      "features": ["libdeflate", "ssl", "zlib"]
    }
  ],
  "vcpkg-configuration": {
    "default-registry": {
      "kind": "git",
      "repository": "https://github.com/Microsoft/vcpkg",
      "baseline": "4002e3abc6d3e468c73d2d9777a7dd96af5dc224"
    }
  }
}

vcpkg install --triplet x64-linux-release
// installation was sucessfull got following files installed into my project directory:
vcpkg_installed
vcpkg_installed/vcpkg
vcpkg_installed/vcpkg/info
vcpkg_installed/vcpkg/updates
vcpkg_installed/vcpkg/compiler-file-hash-cache.json
vcpkg_installed/vcpkg/issue_body.md
vcpkg_installed/vcpkg/manifest-info.json
vcpkg_installed/vcpkg/status
vcpkg_installed/vcpkg/vcpkg-lock.json
vcpkg_installed/x64-linux
vcpkg_installed/x64-linux/share
vcpkg_installed/x64-linux-release
vcpkg_installed/x64-linux-release/etc
vcpkg_installed/x64-linux-release/include
vcpkg_installed/x64-linux-release/lib
vcpkg_installed/x64-linux-release/share

However, the probelem is then the consuming via cmake:

cmake -S . -GNinja -B build

I have this in my CMakeLists.txt root, which will be executed

if(DEFINED ENV{VCPKG_ROOT})
    message(STATUS "Using vcpkg toolchain from: $ENV{VCPKG_ROOT}")
    set(CMAKE_TOOLCHAIN_FILE "$ENV{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake")
endif()

But fails later with:

find_package(OpenCASCADE CONFIG REQUIRED)
////
CMake Error at CMakeLists.txt:15 (find_package):
  Could not find a package configuration file provided by "OpenCASCADE" with
  any of the following names:

    OpenCASCADEConfig.cmake
    opencascade-config.cmake

What cmd am I missing to tell vcpkg that my cmake package config files are in this project folder under vcpkg_installed/x64-linux-release/share?

What I not understand is, this CMAKE_TOOLCHAIN_FILE "$ENV{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake is a global toolchain file, how will this help to find my local installed libs?

[Osyotr]

Make sure CMAKE_TOOLCHAIN_FILE is set before project(...) is called. Don't forget to clear CMake cache afterwards.

What I not understand is, this CMAKE_TOOLCHAIN_FILE "$ENV{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake is a global toolchain file, how will this help to find my local installed libs?

vcpkg.cmake overrides find_package to inject paths relative to to the installed tree (which is a subfolder of your build folder by default).

[acki-m]

but how is something in my /usr/local/vcpkg/scripts/buildsystems/vcpkg.cmake, will find something in /workspace/project/vcpkg_installed?

[Osyotr]

When vcpkg toolchain is loaded, it already knows your CMAKE_BINARY_DIR, VCPKG_TARGET_TRIPLET. The installation layout is fixed.

[acki-m]

I did what you said:

 cmake -S . -GNinja -DCMAKE_TOOLCHAIN_FILE=$VCPKG_ROOT/scripts/buildsystems/vcpkg.cmake  -B build
-- Running vcpkg install
warning: Embedding `vcpkg-configuration` in a manifest file is an EXPERIMENTAL feature.
Fetching registry information from https://github.com/Microsoft/vcpkg (HEAD)...
Detecting compiler hash for triplet x64-linux...
Compiler found: /usr/bin/c++
The following packages will be built and installed:
  * egl-registry:x64-linux@2024-01-25 -- git+https://github.com/Microsoft/vcpkg@d883db43133dd223c4ffdbef4193943f6784d43a
  * libdeflate[compression,core,decompression,gzip,zlib]:[email protected] -- git+https://github.com/Microsoft/vcpkg@57bfea438c023e4d0ca593f215a5f81eaa390151
    opencascade[core,rapidjson]:[email protected] -- git+https://github.com/Microsoft/vcpkg@5698eb483bbce42fd662a7682d880c5e24d24a68
  * opengl:x64-linux@2022-12-04#3 -- git+https://github.com/Microsoft/vcpkg@c3ae71738f88449ebcd781cef60d9a253fa091d4
  * opengl-registry:x64-linux@2024-02-10#1 -- git+https://github.com/Microsoft/vcpkg@22f7aa58ee78c9f0db904b6251e9265f2be26f9d
  * openssl:[email protected] -- git+https://github.com/Microsoft/vcpkg@ce87a54727bd8a845487174b4cc04edd00348cfb
  * rapidjson:x64-linux@2025-02-26 -- git+https://github.com/Microsoft/vcpkg@4297a243aa0e3ed6c3a4c307579914593da5751d
  * usockets[core,ssl]:[email protected]#3 -- git+https://github.com/Microsoft/vcpkg@080448b6175d620e1b986327d0a10caee41946d4
    uwebsockets[core,libdeflate,ssl,zlib]:[email protected] -- git+https://github.com/Microsoft/vcpkg@710a7028c6e4c18cc7ab4779014c737ad7b094ec
  * vcpkg-cmake:x64-linux@2024-04-23 -- git+https://github.com/Microsoft/vcpkg@e74aa1e8f93278a8e71372f1fa08c3df420eb840
  * vcpkg-cmake-config:x64-linux@2024-05-23 -- git+https://github.com/Microsoft/vcpkg@97a63e4bc1a17422ffe4eff71da53b4b561a7841
  * vcpkg-cmake-get-vars:x64-linux@2025-05-29 -- git+https://github.com/Microsoft/vcpkg@d6510f888dd526c7828f6b973349e7f30be51254
  * zlib:[email protected] -- git+https://github.com/Microsoft/vcpkg@3f05e04b9aededb96786a911a16193cdb711f0c9

However, it looks like it will start build again (I wanted to use only the release libraries as dependency) and it looks like it will build in a global cache. I dont wanted both of this. Why is vcpkg not using my local install cached under /project_dir/vcpkg_installed?

Maybe I am missing a nice tutorial what is the current way to use vcpkg with release dependencies and a json manifest file.

[Osyotr]

Have you set VCPKG_TARGET_TRIPLET (and VCPKG_HOST_TRIPLET) to x64-linux-release?
You can control vcpkg_installed location using VCPKG_INSTALLED_DIR.
https://learn.microsoft.com/en-us/vcpkg/users/buildsystems/cmake-integration

[acki-m]

I set in my Dockerfile now:

ENV VCPKG_MANIFEST_MODE=ON
ENV VCPKG_TARGET_TRIPLET=x64-linux-release

This works better, however, it will still try to compile a debug version. Or is this a normal behavior of vcpkg? Or am I missing an option?

Anyway, what is your recommendation for using vcpkg and Docker, so that the cache is not invalidaded when rebuild or restarted the container?

[Osyotr]

Both of these variables are not environment variables, they are CMake cache variables so you should be passing them to CMake.
Except that you shouldn't pass VCPKG_MANIFEST_MODE explicitly because it defaults to ON if there's a manifest file in your project's top level directory.

[acki-m]

One Additional question which goes out of scope of the original (or better start a new disucssion?):
What is your recommendation for using vcpkg and Docker, so that the cache is not invalidaded when rebuild or restarted the container?

[Osyotr]

Use binary caching
https://learn.microsoft.com/en-us/vcpkg/consume/binary-caching-local