CMAKE_NINJA_OUTPUT_PATH_PREFIX ------------------------------ .. versionadded:: 3.6 Set output files path prefix for the :generator:`Ninja` generator. Every output files listed in the generated ``build.ninja`` will be prefixed by the contents of this variable (a trailing slash is appended if missing). This is useful when the generated ninja file is meant to be embedded as a ``subninja`` file into a *super* ninja project. For example, a ninja build file generated with a command like:: cd top-build-dir/sub && cmake -G Ninja -DCMAKE_NINJA_OUTPUT_PATH_PREFIX=sub/ path/to/source can be embedded in ``top-build-dir/build.ninja`` with a directive like this:: subninja sub/build.ninja The ``auto-regeneration`` rule in ``top-build-dir/build.ninja`` must have an order-only dependency on ``sub/build.ninja``. .. note:: When ``CMAKE_NINJA_OUTPUT_PATH_PREFIX`` is set, the project generated by CMake cannot be used as a standalone project. No default targets are specified.