CMP0048 — CMake 4.0.1 Documentation

# CMP0048

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 `project()` command manages `VERSION` variables.

CMake version 3.0 introduced the `VERSION` option of the `project()` command to specify a project version as well as the name. In order to keep `PROJECT_VERSION` and related variables consistent with variable `PROJECT_NAME` it is necessary to set the `VERSION` variables to the empty string when no `VERSION` is given to `project()`. However, this can change behavior for existing projects that set `VERSION` variables themselves since `project()` may now clear them. This policy controls the behavior for compatibility with such projects.

The `OLD` behavior for this policy is to leave `VERSION` variables untouched. The `NEW` behavior for this policy is to set `VERSION` as documented by the `project()` command.

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.