CMP0074ΒΆ
find_package() uses PackageName_ROOT variables.
In CMake 3.12 and above the find_package(PackageName) command now searches
a prefix specified by a PackageName_ROOT CMake or environment variable.
Package roots are maintained as a stack so nested calls to all find_*
commands inside find modules also search the roots as prefixes. This policy
provides compatibility with projects that have not been updated to avoid using
PackageName_ROOT variables for other purposes.
The OLD behavior for this policy is to ignore PackageName_ROOT
variables. The NEW behavior for this policy is to use PackageName_ROOT
variables.
This policy was introduced in CMake version 3.12. CMake version
3.12.0 warns when the policy is not set and uses OLD behavior.
Use the cmake_policy() command to set it to OLD or NEW
explicitly.
Note
The OLD behavior of a policy is
deprecated by definition
and may be removed in a future version of CMake.