CTEST_PARALLEL_LEVEL

.. include:: include/ENV_VAR.rst

Specify the number of tests for CTest to run in parallel. For example, if CTEST_PARALLEL_LEVEL is set to 8, CTest will run up to 8 tests concurrently as if ctest were invoked with the :option:--parallel 8 <ctest --parallel> option.

.. versionchanged:: 3.29

The value may be empty, or 0, to let ctest use a default level of parallelism, or unbounded parallelism, respectively, as documented by the :option:ctest --parallel option.

CTest will interpret a whitespace-only string as empty.

In CMake 3.28 and earlier, an empty or 0 value was equivalent to 1.

See :manual:ctest(1) for more information on parallel test execution.