CMP0050

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().

Disallow add_custom_command SOURCE signatures.

CMake 2.8.12 and lower allowed a signature for add_custom_command() which specified an input to a command. This was undocumented behavior. Modern use of CMake associates custom commands with their output, rather than their input.

The OLD behavior for this policy is to allow the use of add_custom_command() SOURCE signatures. The NEW behavior for this policy is to issue an error if such a signature is used.

This policy was introduced in CMake version 3.0. 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.