CMP0125 — CMake 4.3.1 Documentation

# CMP0125

Added in version 3.21.

The `find_file()`, `find_path()`, `find_library()` and `find_program()` commands cache their result in the variable specified by their first argument. Prior to CMake 3.21, if a cache variable of that name already existed before the call but the cache variable had no type, any non-cache variable of the same name would be discarded and the cache variable was always used (see also `CMP0126` for a different but similar behavior). This contradicts the convention that a non-cache variable should take precedence over a cache variable of the same name. Such a situation can arise if a user sets a cache variable on the command line without specifying a type, such as `cmake -DMYVAR=blah ...` instead of `cmake -DMYVAR:FILEPATH=blah`.

Related to the above, if a cache variable of the specified name already exists and it does have a type, the various `find_...()` commands would return that value unchanged. In particular, if it contained a relative path, it would not be converted to an absolute path in this situation.

When policy `CMP0125` is set to `OLD` or is unset, the behavior is as described above. When it is set to `NEW`, the behavior is as follows:

- If a non-cache variable of the specified name exists when the `find_...()` command is called, its value will be used regardless of whether a cache variable of the same name already exists or not. A cache variable will not be created in this case if no such cache variable existed before. If a cache variable of the specified name did already exist, the cache will be updated to match the non-cache variable.

- The various `find...()` commands will always provide an absolute path in the result variable, except where a relative path provided by a cache or non-cache variable cannot be resolved to an existing path.

This policy was introduced in CMake version 3.21. It may be set by `cmake_policy()` or `cmake_minimum_required()`. If it is not set, CMake does not warn, 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.