CMP0009 — CMake 4.3.0 Documentation

# CMP0009

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()`.

FILE GLOB_RECURSE calls should not follow symlinks by default.

In CMake 2.6.1 and below, `file(GLOB_RECURSE)` calls would follow through symlinks, sometimes coming up with unexpectedly large result sets because of symlinks to top level directories that contain hundreds of thousands of files.

This policy determines whether or not to follow symlinks encountered during a `file(GLOB_RECURSE)` call. The `OLD` behavior for this policy is to follow the symlinks. The `NEW` behavior for this policy is not to follow the symlinks by default, but only if `FOLLOW_SYMLINKS` is given as an additional argument to the `FILE` command.

This policy was introduced in CMake version 2.6.2. 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.