CODEWITHSUNDEEP
c++powershellcmakepybind11python-embedding
bwolf
bwolf

Reputation: 317

How to make cmake find pybind11

I am trying to follow the simple example for embedding python within c++ using pybind11 as found on this page. However, when trying to use cmake to build the solution, I keep getting an error that says

By not providing "Findpybind11.cmake" in CMAKE_MODULE_PATH this project has asked CMake to find a package configuration file provided by "pybind11", but CMake did not find one.

Could not find a package configuration file provided by "pybind11" with any of the following names:

pybind11Config.cmake
pybind11-config.cmake

I have a folder called pybindtest on my Desktop which includes CMakeLists.txt and main.cpp as described in the link above, as well as a build folder that I created. While in the build folder, I have tried the following lines to no avail (running on Powershell 7):

cmake ..
cmake .. -Dpybind11_DIR=C:/Users/ben.wolfley/Anaconda3/Library/share/cmake/pybind11/pybind11Config.cmake
cmake .. -DCMAKE_MODULE_PATH=C:/Users/ben.wolfley/Anaconda3/Library/share/cmake/pybind11

I installed pybind11 using conda install pybind11, and pybind11Config.cmake is in C:\Users\ben.wolfley\Anaconda3\Library\share\cmake\pybind11

Upvotes: 17

Views: 26151

Answers (6)

midiexiang
midiexiang

Reputation: 1

the command

pip install pybind11

doesn't install the pybing11Config.cmake file in your system path,so CMAKE couldn't find it;but it does installed the file at the /path/to/the/python/env/python_version/lib/site-packages/pybind11/share/cmake/pybind11,in my case,is:

/home/run/miniconda3/envs/py311/lib/python3.11/site-packages/pybind11/share/cmake/pybind11

I recommend that you temporary add that path to CMAKE_PREFIX_PATH：

export CMAKE_PREFIX_PATH=/home/run/miniconda3/envs/py311/lib/python3.11/site-packages/pybind11/share/cmake/pybind11:$CMAKE_PREFIX_PATH

by adding this, CMAKE can find pybing11,and CMakeCache.txt will remember it, so that you haven't need to add the line every time.

Upvotes: 0

Simon.lee
Simon.lee

Reputation: 21

In my case, Ubuntu 22.04 LTS, python 3.10

pip install pybind11

or

pip3 install pybind11

this command will install at your local lib, bin path under /home so, you can find .cmake files as the below path

/home/your_account/.local/lib/python3.10/site-packages/pybind11/share/cmake/pybind11

edit CMakeLists.txt

set(pybind11_DIR /home/your_account/.local/lib/python3.10/site-packages/pybind11/share/cmake/pybind11)

find_package(pybind11 REQUIRED)

Upvotes: 2

Caleb
Caleb

Reputation: 416

Add following to CMakeLists.txt:

# set pybind11 dir
set(pybind11_DIR /Users/Caleb/Softwares/pybind11)
find_package(pybind11 REQUIRED)

Upvotes: 4

BuvinJ
BuvinJ

Reputation: 11046

I followed this tutorial to get started with pybind11: https://www.blopig.com/blog/2021/03/c-python-bindings-in-5-minutes/ That works VERY easily, and doesn't require having a CMake script all at.

But... I wanted to edit my code from within my IDE of choice (Qt Creator), and have that provide intellisense for me and whatnot. As such, I added CMake to the project for that benefit (Qt Creator can lean on it).

So, to get my IDE to simply not complain about missing includes (and to even compile the code if I want - though not actually build the whole pybind wrapper), all I needed to do was add a couple of include paths. In my environment, they were as follows:

include_directories(/usr/include/python3.6m)
include_directories(/home/johndoe/.local/lib/python3.6/site-packages/pybind11/include)

That, of course, is not portable. So to address that, I dropped in a macro which would allow me to implement a better solution using environmental variables:

macro(include_envvar_directory varname)
    if(DEFINED ENV{${varname}})
        set(dir_path $ENV{${varname}})
    else()
        message(FATAL_ERROR "ERROR: Env var ${varname} must be defined!")
    endif()
    if(NOT EXISTS ${dir_path})
        message(FATAL_ERROR
            "ERROR: Invalid path: ${dir_path} specified by env var: ${varname}")
    endif()
    message(STATUS "Adding to include path: ${dir_path}")
    include_directories(${dir_path})
endmacro()

include_envvar_directory(PY_INCLUDE_PATH)
include_envvar_directory(PYBIND_INCLUDE_PATH)

With that in place, I passed the PY_INCLUDE_PATH and PYBIND_INCLUDE_PATH env vars to the CMake via the IDE's feature to define such per project / workstation.

Upvotes: 1

KeitelDOG
KeitelDOG

Reputation: 5180

In case someone having the same issue without Anaconda, like directly with pip pybind11 or manual clone installation, both caused problems in my case. Manual installation of pybind11 with git didn't install the cmake config pybind11Config.cmake, although there is a tools/pybind11Config.cmake.in file, that I couldn't turn into a proper pybind11Config.cmake.

Installation pybind11 global with pip solved it for me, and automatically uninstalled the manual git installation:

pip install "pybind11[global]"

which installed both pybind11 and pybind11-global with proper cmake config like Anaconda does.

Upvotes: 20

bwolf
bwolf

Reputation: 317

Thanks to Tsyvarev for pointing me in the right direction. The following command worked:

cmake .. -G "Visual Studio 15 2017" -A x64 `
      -Dpybind11_DIR=C:/Users/ben.wolfley/Anaconda3/Library/share/cmake/pybind11/

I was pointing to the .cmake file instead of the file's directory. I also had to specify the compiler in order for the code to work.

Upvotes: 2

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