# CMP0014

Input directories must have `CMakeLists.txt`.

CMake versions before 2.8 silently ignored missing `CMakeLists.txt` files in directories referenced by `add_subdirectory()` or `subdirs()`, treating them as if present but empty. In CMake 2.8.0 and above this `cmake_policy()` determines whether or not the case is an error. The `OLD` behavior for this policy is to silently ignore the problem. The `NEW` behavior for this policy is to report an error.

This policy was introduced in CMake version 2.8.0. CMake version 3.16.0-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.