Q:

Have a CMake project default to the Release build type

How should I make my CMake project default to configuration for a Release rather than a Debug build?

A:

You could try the following:
if (NOT EXISTS ${CMAKE_BINARY_DIR}/CMakeCache.txt)
  if (NOT CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE "Release" CACHE STRING "" FORCE)
  endif()
endif()

