How do I use nested vcpkg manifests in submodules/sub-projects? #18122

mikepricedev · 2020-12-24T00:40:45Z

mikepricedev
Dec 24, 2020

├── CMakeLists.txt
├── vcpkg.json
├── vcpkg_installed
├── extern
│   ├── CMakeLists.txt
│   ├── sub_project
│   │   ├── CMakeLists.txt
│   │   ├── vcpkg.json
│   │   ├── vcpkg_installed

In the above folder structure the "sub_project" submodule uses vcpkg and a vcpkg.json manifest to manage its deps. The root project also uses vcpkg and a vcpkg.json manifest to manage deps.

However, when the project is configured the sub_project's CMakeLists.txt vcpkg wiring no longer finds packages installed in sub_project/vcpkg_installed dir.
Steps taken:

vcpkg install ran in sub_project dir. vcpkg_installed dir was created as expected.
PATHS option added to find_package in submodule cmake. (in my case using the frozen lib)

find_package(frozen REQUIRED
  PATHS "${CMAKE_CURRENT_SOURCE_DIR}/vcpkg_installed/${VCPKG_TARGET_TRIPLET}"
)

Step 2 finds the library (frozen), but when compiling generates: 'frozen/map.h' file not found #include <frozen/map.h> not an issue in sub_project standalone.
The following correctly prints the include dirs.

get_target_property(frozeninc frozen::frozen INTERFACE_INCLUDE_DIRECTORIES)
message(STATUS "frozen INTERFACE_INCLUDE_DIRECTORIES: ${frozeninc}")

Note: using vcpkg as a submodule technique in both i.e.

set(
  CMAKE_TOOLCHAIN_FILE "${CMAKE_CURRENT_SOURCE_DIR}/extern/vcpkg/scripts/buildsystems/vcpkg.cmake"
  CACHE STRING "Vcpkg toolchain file")

NancyLi1013 · 2020-12-24T06:48:29Z

NancyLi1013
Dec 24, 2020

Hi @mikepricedev

Thanks for posting this issue.

You might forget to add target_link_libraries(main PRIVATE frozen::frozen frozen::frozen-headers) in your CMakeLists.txt.

Could you please refer to the usage of frozen to rebuild your project?

 find_package(frozen CONFIG REQUIRED)
 target_link_libraries(main PRIVATE frozen::frozen frozen::frozen-headers)

0 replies

NancyLi1013 · 2020-12-30T07:21:34Z

NancyLi1013
Dec 30, 2020

@mikepricedev

Please let me know if the above suggestion can work for you.

0 replies

mikepricedev · 2020-12-30T20:51:57Z

mikepricedev
Dec 30, 2020
Author

@NancyLi1013
Thank you so much for taking a look. Before I go further I realized I am making an assumption that I haven't found any specific documentation. Does vcpkg support project's using vcpkg.json that have submodules that also use vcpkg.json? I'm using the following technique to add my submodules to my root project's CMakeLists.txt.

add_subdirectory(extern/sub_project)

In my case, Frozen is a dep of the sub_project managed in the sub_project by a vcpkg.json manifest. When I build the sub_project project independently (not as a submodule) the #include <frozen/map.h> is not an issue.

It is only when the sub_project is built as a submodule of another project using vcpkg. Both projects have vcpkg.json mainfest files. If I hoist the dependencies from the sub_project and paste them into the root project's vcpkg.json dependencies . There is no issue.

I also noticed something else particular. The sub_project also has a dep to "boost-smart-ptr". When I build the sub_project independenly boost is found in the vcpkg_installed dir. When built as a submodule the dep is found from my system's copy of "boost". I do not have a system copy of "frozen".

0 replies

PhoebeHui · 2021-03-05T08:43:09Z

PhoebeHui
Mar 5, 2021
Collaborator

@mikepricedev, does this still be a question for you?

From manifests.md, when invoked from any subdirectory of the directory containing vcpkg.json, vcpkg install with no package arguments will install all manifest dependencies into /vcpkg_installed/.

0 replies

cyraid · 2021-04-05T05:32:25Z

cyraid
Apr 5, 2021

I'm running into this problem too.. But I'm relying on visual studio 2019 cmake support to use vcpkg. It seems to be ignoring the sub directory/sub directory.

Is there support for add_subdirectory and sub directories with their own vcpkg.json? (And just using the main project without opening separate visual studio 2019 instances with their own cmakelists.txt).

0 replies

strega-nil · 2021-04-07T19:26:36Z

strega-nil
Apr 7, 2021

@cyraid there is currently no support for having multiple top level manifests. We have considered some ways to solve this, but none of them very good. If you're interested in solving this issue, please open a discussion topic about it. Otherwise, writing a top-level vcpkg.json that contains all of the dependencies your subdirectories need, or alternatively using vcpkg to manage these dependencies as well, are the two solutions we see right now.

0 replies

cyraid · 2021-04-07T19:59:47Z

cyraid
Apr 7, 2021

Hi @strega-nil ! Thank you for the reply! Where would you guys like to discuss this? I mean, I don't have much time to talk about it but my quick input would be to add a ADD_TARGET_VCPKG in the sub directory inside that CMakeLists.txt. So, ADD_LIBRARY(MyPlugin), and then ADD_TARGET_VCPKG(MyPlugin). This way you could add the appropriate includes and properties etc. for that target. This would of course also call vcpkg in that directory too, but perhaps with the same cache directory and out from CMakeSettings.json?

0 replies

strega-nil · 2021-04-08T16:57:15Z

strega-nil
Apr 8, 2021

@cyraid https://github.com/microsoft/vcpkg/discussions

0 replies

kentf · 2021-08-02T13:30:17Z

kentf
Aug 2, 2021

We'd also like to have nested vcpkg.json support.

We have many projects in a small monorepo. Some of the projects require some larger dependencies (OpenCV, Qt), while some only requires header only libraries.

The projects can be added/excluded from the solution by CMake option toggles. It would be nice to only acquire/build, say Qt and OpenCV, if the projects that uses those dependencies are being configured and built.

1 reply

ras0219-msft Aug 2, 2021
Collaborator

You can use features for this: https://github.com/microsoft/vcpkg/blob/master/docs/users/manifests.md#vcpkg_manifest_features

ras0219-msft · 2021-08-02T22:13:04Z

ras0219-msft
Aug 2, 2021
Collaborator

Vcpkg doesn't support separate vcpkg.json files in this manner; instead, you'll need to add the inner dependencies to the outer vcpkg.json file. For CMake, only the vcpkg.json adjacent to the top-level CMakeLists.txt is considered.

12 replies

petersteneteg Oct 2, 2024

@derekcyruschow-catapult it is quite specific to our workflow, but you might get some inspiration https://github.com/inviwo/inviwo/blob/71f4dd278595367a84d1c1cb8317fe9113becb4d/cmake/vcpkg-manifest-generation-toolchain.cmake

parsaiej Dec 28, 2025

Greetings from 2026! Any news on official multi-json support? This current limitation is unfortunate if you want to distribute source for a middleware library that uses vcpkg via submodule. It's not a realistic expectation for a user of the middleware library to merge the json if they too are using vcpkg. They should just be able to add_subdirectory and have it "just work".

dg0yt Jan 2, 2026

They should just be able to add_subdirectory and have it "just work".

IMO this is difficult in a robust "just work" quality. add_directory() typically takes place after toolchain setup, i.e. after project(). Sometimes it is subject to if() conditions.

But vcpkg dependency resolution and installation must be done once and early. With vcpkg manifest mode it takes place during the top-level project(). It can consider features and overlay ports if this information is present at that time. But it doesn't know which subdirectories are visited later.

The robust way which is available now is overlay ports and find_package().

Disclaimer: Community feedback.

dcyruschow-cat Mar 4, 2026

The robust way which is available now is overlay ports and find_package().

@dg0yt sorry I'm not sure I follow, do you have an example of this you can share please?

emusgrave Mar 4, 2026

This probably isn't what @dg0yt was referring to, but what I've found for my own internal projects I can do the following. Maybe it will spawn some ideas for you. In the end it's all just workarounds and I think there are a lot of gotcha's that prevent a robust solution to this being built into vcpkg (because of the version challenges, what baseline is used, etc).

In the subproject, create a "dummy" overlay-port that is just used to list out that subproject's dependencies. So..

# portfile.cmake
set(VCPKG_POLICY_EMPTY_PACKAGE enabled)

# vcpkg.json (in the overlay)
{
  "name": "my-subproject-deps",
  "version": "1.0.0",
  "description": "Meta-port that centralizes manifest dependencies",
  "dependencies": [ ... ]
}

my-subproject's root vcpkg.json can just point to the overlay port and list that as it's only dependency. For my purposes I have vcpkg as a submodule in that subproject and can clone it and work in just that subproject if needed.

# my-subproject's root vcpkg.json
{
  "$schema": "https://raw.githubusercontent.com/microsoft/vcpkg-tool/main/docs/vcpkg.schema.json",
  "name": "my-subproject",
  "version": "1.0.0",
  "dependencies": ["my-subproject-deps"],
  "vcpkg-configuration": {
    "overlay-ports": [
      "./vcpkg-overlay-ports/my-subproject-dep",
    ],
  },
  "builtin-baseline": "..."
}

Then in the parent project, also with vcpkg as a submodule:

Add my-subproject as a git submodule
Add (to root vcpkg.json) the subproject's overlay port and my-subproject-deps to the dependency array.
Configure and build.

# project root vcpkg.json
{
  "$schema": "https://raw.githubusercontent.com/microsoft/vcpkg-tool/main/docs/vcpkg.schema.json",
  "name": "project",
  "version": "1.0.0",
  "dependencies": [
    "my-subproject-deps",
    ... all of my other dependencies ...
  ],
  "vcpkg-configuration": {
    "overlay-ports": [
      "./submodules/my-subproject/vcpkg-overlay-ports/my-subproject-deps",
    ],
}

Hope that helps or spawns some more ideas. Other options could be better, but this satisfied my desire to be able to actively develop in the root project and subproject in parallel without having to jump through hoops every time I want to add another vcpkg dependency to either.

laurentcau · 2024-05-17T09:48:03Z

laurentcau
May 17, 2024

CMakePresets.json uses an include section to solve this issue.

{
        "version": 4,
	"include": [
		"Public/SDK/CMakePresets.json"
	  ]
}

Could that be an option to solve the issue for vcpkg.json too ?

1 reply

JasonDictos Nov 7, 2024

Was just musing over how to solve this as well, we can hijack the fact that vcpkg ignores keys with $ in their name, then with this bash script and a top level "$include": "" value in the vcpkg manifest, this script will install each dependency:

#!/bin/bash

MANIFEST=$1

function pop() {
  popd > /dev/null
}
trap pop EXIT

if [[ ! -f $MANIFEST ]]; then
  echo "usage: ports.sh <manifest.json>"
  exit 1
fi

MANIFEST=$(realpath "$MANIFEST")

readarray -t DEPS < <(cat $MANIFEST | jq -r ".dependencies" | tr -d '[],:{}" ' | sed '/^$/d')

pushd /tmp > /dev/null

for item in ${DEPS[@]}; do
  vcpkg install $item
done

INCLUDE=$(cat $MANIFEST | jq -r '."$include"')
if [[ -f "$INCLUDE" ]]; then
  echo "Found include $INCLUDE"
  $0 "$INCLUDE"
fi

My vcpkg.json this works on:

{
  "name": "sfio",
  "version-string": "1.0.0",
  "$include": "libeen-cpp/vcpkg.json",
  "dependencies": [
    "liburing4cpp",
    "docopt",
    "cli11",
    "boost-lockfree",
    "boost-interprocess",
    "boost-icl",
    "boost-iostreams",
    "boost-crc",
    "boost-accumulators",
    "prometheus-cpp",
    "mio",
    "libmeazure"
  ]
}

Doesn't support vcpkg features or what not, but could be modified to...

How do I use nested vcpkg manifests in submodules/sub-projects? #18122

Uh oh!

Replies: 11 comments · 14 replies

Uh oh!

Uh oh!

Uh oh!

Uh oh!

mikepricedev Dec 30, 2020 Author

Uh oh!

Uh oh!

PhoebeHui Mar 5, 2021 Collaborator

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

ras0219-msft Aug 2, 2021 Collaborator

Uh oh!

Uh oh!

ras0219-msft Aug 2, 2021 Collaborator

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Replies: 11 comments 14 replies

mikepricedev
Dec 30, 2020
Author

PhoebeHui
Mar 5, 2021
Collaborator

ras0219-msft Aug 2, 2021
Collaborator

ras0219-msft
Aug 2, 2021
Collaborator