CMP0208

Added in version 4.3.

export(EXPORT) does not allow empty arguments.

In CMake 4.2 and below, the export(EXPORT) command silently accepted NAMESPACE, FILE or CXX_MODULES_DIRECTORY arguments with empty or missing values.

CMake 4.3 and above issue a diagnostic if any of these keywords are present without an associated value, or of the value given to FILE or CXX_MODULES_DIRECTORY is empty. (NAMESPACE is allowed to have an empty value, but an empty value must be quoted.) A diagnostic is also issued immediately if the value of EXPORT is missing or empty. (Previously, this would result in an error at generate-time because no export set whose name is empty can exist.)

This policy provides compatibility with projects which may have relied on the previous lack of enforcement. The OLD behavior for this policy permits these keywords to be present without an accompanying value, or to be given an empty value. The NEW behavior requires that a value be given, and that the value (except for NAMESPACE) is non-empty.

This policy was introduced in CMake version 4.3. It may be set by cmake_policy() or cmake_minimum_required(). If it is not set, CMake warns, and uses OLD behavior.

Note

The OLD behavior of a policy is deprecated by definition and may be removed in a future version of CMake.