conan: CMAKE_MODULE_PATH not updated in multi-configuration project

Hello, I’d like to create Visual Studio project with Debug and Release mode. In CMakeLists.txt file I have searching for Protobuf (since I have to generate necessary files from *.proto file). Without explicitly setting CMAKE_BUILD_TYPE to either Debug or Release CMAKE_MODULE_PATH isn’t updated with packages root paths and due to that fact searching for library fails.

Code in conanbuildinfo_multi.cmake:

macro(conan_set_find_paths)
    if(CMAKE_BUILD_TYPE)
        if(${CMAKE_BUILD_TYPE} MATCHES "Debug")
            set(CMAKE_PREFIX_PATH ${CONAN_CMAKE_MODULE_PATH_DEBUG} ${CMAKE_PREFIX_PATH})
            set(CMAKE_MODULE_PATH ${CONAN_CMAKE_MODULE_PATH_DEBUG} ${CMAKE_MODULE_PATH})
        else()
            set(CMAKE_PREFIX_PATH ${CONAN_CMAKE_MODULE_PATH_RELEASE} ${CMAKE_PREFIX_PATH})
            set(CMAKE_MODULE_PATH ${CONAN_CMAKE_MODULE_PATH_RELEASE} ${CMAKE_MODULE_PATH})
        endif()
    endif()
endmacro()

For my needs, I had to hack it to this form:

macro(conan_set_find_paths)
    set(CMAKE_PREFIX_PATH ${CONAN_CMAKE_MODULE_PATH_RELEASE} ${CMAKE_PREFIX_PATH})
    set(CMAKE_MODULE_PATH ${CONAN_CMAKE_MODULE_PATH_RELEASE} ${CMAKE_MODULE_PATH})
endmacro()

Do you think, that something should be improved? I don’t want to specify CMAKE_BUILD_TYPE, because it will enable only one configuration in Visual project.

About this issue

Original URL
State: closed
Created 7 years ago
Reactions: 1
Comments: 18 (8 by maintainers)

Most upvoted comments

This is a known limitation of cmake. Paths for modules, and cmake config files, cannot be multiple, they don’t work for multi-config environments like visual studio. So the cmake_multi generator cannot help with this, because CMake is only able to find the path to 1 variant, the debug or the release one, but not both.

I suggest to try these two different approaches:

Do not use cmake Find features at all. Conan already models all the information needed to locate and use the package, so no need to “find” them. You can directly use the conan created variables.
Use multi-configuration packages. You can try creating your own packages that package together the debug and release artifacts: http://docs.conan.io/en/latest/packaging/package_info.html#multi-configuration-packages

It is possible that what you might be suffering (regarding the first approach), is something related to the protobuf package. If the protobuf package just adds itself to the path in env_info consumers can directly invoke protoc without having to do anything special, directly in the conanfile, something that I find really convenient.

memsharded on Jul 13, 2017