New in version 3.12.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Specifies the maximum number of concurrent processes to use when building using the cmake --build command line Build Tool Mode. For example, if CMAKE_BUILD_PARALLEL_LEVEL is set to 8, the underlying build tool will execute up to 8 jobs concurrently as if cmake --build were invoked with the --parallel 8 option.

If this variable is defined empty the native build tool's default number is used.