ENH: If not set, choose Release BUILD_TYPE

Prefer to build in Release mode if not set.

Author: hjmjohnson

CMakeLists.txt

@@ -2,6 +2,17 @@ cmake_minimum_required(VERSION 3.27)
 
 project(PythonQt LANGUAGES CXX VERSION 3.5.6)
 
+#-----------------------------------------------------------------------------
+# Set a default build type if none was specified
+if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
+  message(STATUS "Setting build type to 'Release' as none was specified.")
+  set(CMAKE_BUILD_TYPE Release CACHE STRING "Choose the type of build." FORCE)
+  mark_as_advanced(CMAKE_BUILD_TYPE)
+  # Set the possible values of build type for cmake-gui
+  set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release" "RelWithDebInfo")
+endif()
+#-----------------------------------------------------------------------------
+
 enable_testing()
 
 set(CMAKE_CXX_STANDARD 11)