Problem:
When a project has local Conan recipes (not on ConanCenter), there is no way to tell the cmake-conan provider to export them before it runs conan install on the first find_package() call. Because the provider runs conan install automatically, the local recipes must already be in the Conan cache — but there is no hook in the provider to make that happen.
Current workaround:
Manually calling conan export via execute_process in CMakeLists.txt, guarded by a stamp file to avoid re-exporting on every configure:
cmake_minimum_required(VERSION 3.25)
set(CMAKE_PROJECT_TOP_LEVEL_INCLUDES "conan_provider.cmake")
project(MyProject)
# Must run before the first find_package() so local recipes are in the cache
# before the provider invokes conan install.
if(PROJECT_IS_TOP_LEVEL)
find_program(CONAN_CMD conan REQUIRED)
file(GLOB recipe_dirs CONFIGURE_DEPENDS LIST_DIRECTORIES true "${CMAKE_SOURCE_DIR}/conan/recipes/*/")
foreach(recipe_dir ${recipe_dirs})
if(EXISTS "${recipe_dir}/conanfile.py")
set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS "${recipe_dir}/conanfile.py")
cmake_path(GET recipe_dir FILENAME recipe_name)
set(stamp "${CMAKE_BINARY_DIR}/conan_export_${recipe_name}.stamp")
if("${recipe_dir}/conanfile.py" IS_NEWER_THAN "${stamp}")
execute_process(
COMMAND "${CONAN_CMD}" export "${recipe_dir}"
COMMAND_ERROR_IS_FATAL ANY
)
file(TOUCH "${stamp}")
endif()
endif()
endforeach()
endif()
# Provider runs conan install here, on the first find_package().
find_package(my-local-package REQUIRED)This works but is boilerplate that every project with local recipes has to reinvent.
Proposed solution
A CONAN_LOCAL_RECIPES_DIR variable pointing at a directory of recipes. The provider would glob for conanfile.py files under it, export each one before invoking conan install, and handle the stamp logic internally:
cmake_minimum_required(VERSION 3.25)
set(CMAKE_PROJECT_TOP_LEVEL_INCLUDES "conan_provider.cmake")
set(CONAN_LOCAL_RECIPES_DIR "${CMAKE_SOURCE_DIR}/conan/recipes/")
project(MyProject)
find_package(my-local-package REQUIRED) # provider exports local recipes, then runs conan install
The provider would handle the stamp logic and error reporting internally, keeping CMakeLists.txt clean.
Problem:
When a project has local Conan recipes (not on ConanCenter), there is no way to tell the cmake-conan provider to export them before it runs conan install on the first find_package() call. Because the provider runs conan install automatically, the local recipes must already be in the Conan cache — but there is no hook in the provider to make that happen.
Current workaround:
Manually calling
conan exportviaexecute_processinCMakeLists.txt, guarded by a stamp file to avoid re-exporting on every configure:This works but is boilerplate that every project with local recipes has to reinvent.
Proposed solution
A CONAN_LOCAL_RECIPES_DIR variable pointing at a directory of recipes. The provider would glob for conanfile.py files under it, export each one before invoking conan install, and handle the stamp logic internally:
The provider would handle the stamp logic and error reporting internally, keeping CMakeLists.txt clean.