Search paths

Scikit-build-core populates CMake search paths to take into account any other CMake project installed in the same environment. In order to take advantage of this the dependent project must populate a cmake.* entry-point:

Entry-point group	CMake variable populated	Typical use
cmake.root	<PackageName>_ROOT	find_package(MyProject) (recommended)
cmake.prefix	CMAKE_PREFIX_PATH	catch-all for find_package, find_program, find_path
cmake.module	CMAKE_MODULE_PATH	CMake modules loaded with include(...)

<PackageName>_ROOT

This is the recommended interface to be used for importing dependent packages using find_package. This variable is populated by the dependent project’s entry-point cmake.root.

To configure the cmake.root entry-point to export to other projects, you can use the CMake standard install paths in your CMakeLists.txt if you use wheel.install-dir option, e.g.

CMakeLists.txt

include(CMakePackageConfigHelpers)
include(GNUInstallDirs)
write_basic_package_version_file(
    MyProjectConfigVersion.cmake
    VERSION ${PROJECT_VERSION}
    COMPATIBILITY SameMajorVersion
)
configure_package_config_file(
    cmake/MyProjectConfig.cmake.in
    MyProjectConfig.cmake
    INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/MyProject
)
install(FILES
    ${CMAKE_CURRENT_BINARY_DIR}/MyProjectConfigVersion.cmake
    ${CMAKE_CURRENT_BINARY_DIR}/MyProjectConfig.cmake
    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/MyProject
)

pyproject.toml

[tool.scikit-build]
wheel.install-dir = "myproject"

[project.entry-points."cmake.root"]
MyProject = "myproject"

With this any consuming project that depends on this would automatically work with find_package(MyProject) as long as it is in the build-system.requires list.

CMAKE_PREFIX_PATH

Another common search path that scikit-build-core populates is the CMAKE_PREFIX_PATH which is a common catch-all for all CMake search paths, e.g. find_package, find_program, find_path. This is populated by default with the site-packages folder where the project will be installed or the build isolation’s site-packages folder. This default can be disabled by setting

[tool.scikit-build]
search.site-packages = false

You can also extend CMAKE_PREFIX_PATH with arbitrary paths through the env table.

Additionally, scikit-build-core reads the entry-point cmake.prefix of the dependent projects, which is similarly exported as

[project.entry-points."cmake.prefix"]
MyProject = "myproject"

CMAKE_MODULE_PATH

Scikit-build-core also populates CMAKE_MODULE_PATH variable used to search for CMake modules using the include() command (if the .cmake suffix is omitted). This is populated by reading the entry-point cmake.module of the dependent projects, which is similarly exported as

[project.entry-points."cmake.module"]
MyProject = "myproject"