CMP0034 — CMake 4.2.6 Documentation

# CMP0034

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()`.

The `utility_source()` command should not be called.

This command was introduced in March 2001 to help build executables used to generate other files. This approach has long been replaced by `add_executable()` combined with `add_custom_command()`.

CMake >= 3.0 prefer that this command never be called. The `OLD` behavior for this policy is to allow the command to be called. The `NEW` behavior for this policy is to issue a `FATAL_ERROR` when the command is called.

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.