New in version 3.15.

A ;-list of files or directories that will be removed as a part of the global clean target. It is useful for specifying generated files or directories that are used by multiple targets or by CMake itself, or that are generated in ways which cannot be captured as outputs or byproducts of custom commands.

If an additional clean file is specific to a single target only, then the ADDITIONAL_CLEAN_FILES target property would usually be a better choice than this directory property.

Relative paths are allowed and are interpreted relative to the current binary directory.

Contents of ADDITIONAL_CLEAN_FILES may use generator expressions.

This property only works for the Ninja and the Makefile generators. It is ignored by other generators.