CMAKE_FIND_REQUIRED

在 4.1 版被加入.

If enabled, the following commands are treated as having the REQUIRED keyword unless provided with the OPTIONAL keyword:

• find_package()

• find_program()

• find_library()

• find_path()

• find_file()

When find_package() loads a Find<PackageName>.cmake or <PackageName>Config.cmake module, the CMAKE_FIND_REQUIRED variable is automatically unset within it to restore the default behavior for nested find operations. The module is free to set the CMAKE_FIND_REQUIRED variable itself to opt-in to the behavior.

Note that enabling this variable breaks some commonly used patterns. Multiple calls to find_package() are sometimes used to obtain a different search order to the default.

See also the CMAKE_REQUIRE_FIND_PACKAGE_<PackageName> for making a find_package() call REQUIRED, and for additional information on how enabling these variables can break commonly used patterns.