# CMAKE_DEFAULT_BUILD_TYPE

Added in version 3.17.

Specifies the configuration to use by default in a `build.ninja` file in the `Ninja Multi-Config` generator. If this variable is specified, `build.ninja` uses build rules from `build-<Config>.ninja` by default. All custom commands are executed with this configuration. If the variable is not specified, the first item from `CMAKE_CONFIGURATION_TYPES` is used instead.

The value of this variable must be one of the items from `CMAKE_CONFIGURATION_TYPES`.