# CMP0017

Prefer files from the CMake module directory when including from there.

Starting with CMake 2.8.4, if a cmake-module shipped with CMake (i.e. located in the CMake module directory) calls `include()` or `find_package()`, the files located in the CMake module directory are preferred over the files in `CMAKE_MODULE_PATH`. This makes sure that the modules belonging to CMake always get those files included which they expect, and against which they were developed and tested. In all other cases, the files found in `CMAKE_MODULE_PATH` still take precedence over the ones in the CMake module directory. The `OLD` behavior is to always prefer files from CMAKE_MODULE_PATH over files from the CMake modules directory.

This policy was introduced in CMake version 2.8.4. CMake version 3.28.0-rc1 warns when the policy is not set and uses `OLD` behavior. Use the `cmake_policy()` command to set it to `OLD` or `NEW` explicitly.

Note

The `OLD` behavior of a policy is `deprecated by definition` and may be removed in a future version of CMake.