project() command manages
CMake version 3.0 introduced the
VERSION option of the
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
to the empty string when no
VERSION is given to
However, this can change behavior for existing projects that set
variables themselves since
project() may now clear them.
This policy controls the behavior for compatibility with such projects.
OLD behavior for this policy is to leave
VERSION variables untouched.
NEW behavior for this policy is to set
VERSION as documented by the
This policy was introduced in CMake version 3.0.
CMake version 3.23.20220523-g722a9a6 warns when the policy is not set and uses
OLD behavior. Use the
cmake_policy() command to set
OLD behavior of a policy is
deprecated by definition
and may be removed in a future version of CMake.