CMAKE_BUILD_TYPE
----------------

Specifies the build type on single-configuration generators.

This statically specifies what build type (configuration) will be
built in this build tree.  Possible values are empty, Debug, Release,
RelWithDebInfo and MinSizeRel.  This variable is only meaningful to
single-configuration generators (such as make and Ninja) i.e.  those
which choose a single configuration when CMake runs to generate a
build tree as opposed to multi-configuration generators which offer
selection of the build configuration within the generated build
environment.  There are many per-config properties and variables
(usually following clean SOME_VAR_<CONFIG> order conventions), such as
CMAKE_C_FLAGS_<CONFIG>, specified as uppercase:
CMAKE_C_FLAGS_[DEBUG|RELEASE|RELWITHDEBINFO|MINSIZEREL].  For example,
in a build tree configured to build type Debug, CMake will see to
having CMAKE_C_FLAGS_DEBUG settings get added to the CMAKE_C_FLAGS
settings.  See also CMAKE_CONFIGURATION_TYPES.