[question] Extend CMAKE_MODULE_PATH/CMAKE_PREFIX_PATH at consumers

[aagor]

What is your question?

Hi,

I want to package some CMake build scripts in a conan package.
For include(some-build-script.cmake) to work at consumers of this package, they must add the path of the CMake scripts to its CMAKE_PREFIX_PATH / CMAKE_MODULE_PATH.

I have not seen a way to conveniently add something like this.
The attributes that can be set inside package_info() don't cover this case.

Have I missed something?
What's the best solution for this problem?

Have you read the CONTRIBUTING guide?

• I've read the CONTRIBUTING guide

[memsharded]

Hi @aagor

I think you are interested in https://docs.conan.io/2/examples/graph/requires/consume_cmake_macro.html

Basically you need to self.cpp_info.builddirs = ["path/with/cmake"] so this path is added to the CMAKE_ paths (via conan_toolchain.cmake from CMakeToolchain

[aagor]

Hi @memsharded,

thanks, that is exactly what I asked for. I must have missed that.

May I suggest to extend the documentation of find_paths inside the CMakeToolchain documentation, to make that more easily discoverable when searching the documentation for CMAKE_XXXX_PATH (and maybe link the example somewhere)? Adding something like "Also adds the declared builddirs from cpp_info of host dependencies".

[memsharded]

Yes, sounds good, this is pending some more detailed documentation, but it will probably be associated to the new CMakeConfigDeps generator, as this is information more associated to dependencies than to the toolchain.

Moving the ticket to the docs repo.

[michaelmayer]

Hi @memsharded,

are you planning to add the CMAKE_PREFIX_PATH / CMAKE_MODULE_PATH to the CMakeConfigDeps generator as well?

Right now all the paths in conan_toolchain.cmake are excluded when using the new generator, so the include inside the consumers CMakeLists.txt doesn't work anymore.
I was quite happy to discover the new generator recently, because now we can finally ask for CMake DLL_DEPENDENCIES and such for our targets (since they are real "imported" targets now).

thanks,
Michael

[memsharded]

Hi @michaelmayer

This might need a new ticket.

The new CMakeConfigDeps now generates a conan_cmakedeps_paths.cmake file that can be included with:

        # for each pkg_name
        set({{pkg_name}}_DIR "{{folder}}")

        set(CONAN_RUNTIME_LIB_DIRS {{ host_runtime_dirs }} )
        set(CMAKE_VS_DEBUGGER_ENVIRONMENT "PATH=${CONAN_RUNTIME_LIB_DIRS};%PATH%")
        list(PREPEND CMAKE_PROGRAM_PATH {{ cmake_program_path }})
        list(PREPEND CMAKE_LIBRARY_PATH {{ cmake_library_path }})
        list(PREPEND CMAKE_INCLUDE_PATH {{ cmake_include_path }})
        list(PREPEND CMAKE_FRAMEWORK_PATH {{ cmake_framework_path }})

But not explicitly adding the CMAKE_PREFIX_PATH.

But the find_package() should work, and that should put the folders in the CMake paths.
So it would be great to get a new ticket in the Conan client repo, reporting exactly the use case (like include() without a find_package(), or if using the find_package() but it doesn't work, etc).

Thanks!

[memsharded]

Hi @michaelmayer

I am proposing some additions to the docs to close this ticket.
To handle possible changes in CMakeConfigDeps it would be better to create a dedicated new ticket in the Conan main repository, not here in the docs. Thanks!

[memsharded]

Closed by #4065 for next 2.16 release