CMAKE_POLICY_VERSION_MINIMUM

Added in version 4.0.

Specify a minimum Policy Version for a project without modifying its calls to cmake_minimum_required(VERSION) and cmake_policy(VERSION).

This variable should not be set by a project in CMake code as a way to set its own policy version. Use cmake_minimum_required(VERSION) and/or cmake_policy(VERSION) for that. This variable is meant to externally set policies for which a project has not itself been updated:

• Users running CMake may set this variable in the cache, e.g., -DCMAKE_POLICY_VERSION_MINIMUM=3.5, to try configuring a project that has not been updated to set at least that policy version itself.

• Projects may set this variable before a call to add_subdirectory() that adds a third-party project in order to set its policy version without modifying third-party code.

See CMAKE_POLICY_DEFAULT_CMP<NNNN> to set individual policies.