The default CMAKE_BUILD_TYPE is often desired to be set to Release. CMake environment variable CMAKE_BUILD_TYPE can be a convenient user default.

• Linux add to ~/.profile:
• macOS add to ~/.zshrc:

export CMAKE_BUILD_TYPE=Release

• Windows, set CMAKE_BUILD_TYPE=Release via the user environment variable GUI.

We also generally recommend setting the default CMake generator.

For projects used by a range of users who may or may not know to set a default build type, and where the developers want to ensure users are normally getting the full performance of a Release build, use GENERATOR_IS_MULTI_CONFIG:

get_property(gen_multi GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
if(NOT gen_multi AND NOT (CMAKE_BUILD_TYPE OR DEFINED ENV{CMAKE_BUILD_TYPE}))
  set(CMAKE_BUILD_TYPE Release CACHE STRING "Release can have faster run time than Debug")
endif()