# CMP0052

Warning

The `OLD` behavior of this policy was removed in CMake version 4.0. This policy must be set to `NEW` by a call to `cmake_minimum_required()` or `cmake_policy()`.

Added in version 3.1.

Reject source and build dirs in installed `INTERFACE_INCLUDE_DIRECTORIES`.

CMake 3.0 and lower allowed subdirectories of the source directory or build directory to be in the `INTERFACE_INCLUDE_DIRECTORIES` of installed and exported targets, if the directory was also a subdirectory of the installation prefix. This makes the installation depend on the existence of the source dir or binary dir, and the installation will be broken if either are removed after installation.

See Include Directories and Usage Requirements for more on specifying include directories for targets.

The `OLD` behavior for this policy is to export the content of the `INTERFACE_INCLUDE_DIRECTORIES` with the source or binary directory. The `NEW` behavior for this policy is to issue an error if such a directory is used.

This policy was introduced in CMake version 3.1. Prior to removal in CMake version 4.0, it could be set by `cmake_policy()` or `cmake_minimum_required()`. If it was not set, CMake warned, and used `OLD` behavior.