# CMAKE_CROSS_CONFIGS

Added in version 3.17.

Specifies a semicolon-separated list of configurations available from all `build-<Config>.ninja` files in the `Ninja Multi-Config` generator. This variable activates cross-config mode. Targets from each config specified in this variable can be built from any `build-<Config>.ninja` file. Custom commands will use the configuration native to `build-<Config>.ninja`. If it is set to `all`, all configurations from `CMAKE_CONFIGURATION_TYPES` are cross-configs. If it is not specified, or empty, each `build-<Config>.ninja` file will only contain build rules for its own configuration.

The value of this variable must be a subset of `CMAKE_CONFIGURATION_TYPES`.