workaround for a weird behaviour of Shiboken2Config.cmake that may explicitly set CMAKE_BUILD_TYPE to Release

CMakeLists.txt

@@ -1043,7 +1043,12 @@ if(NOT FREECAD_LIBPACK_USE OR FREECAD_LIBPACK_CHECKFILE_CLBUNDLER)
             find_package(PySide REQUIRED HINTS "${PYTHON_LIBRARY_DIR}/cmake")
         endif(DEFINED MACPORTS_PREFIX)
 
+        # Shiboken2Config.cmake may explicitly set CMAKE_BUILD_TYPE to Release which causes
+        # CMake to fail to create Makefiles for a debug build.
+        # So as a workaround we save and restore the value after checking for Shiboken2.
+        set (SAVE_BUILD_TYPE ${CMAKE_BUILD_TYPE})
         find_package(Shiboken2 QUIET)# REQUIRED
+        set (CMAKE_BUILD_TYPE ${SAVE_BUILD_TYPE})
         if (Shiboken2_FOUND)
             # Shiboken2 config file was found but it may use the wrong Python version
             # Try to get the matching config suffix and repeat finding the package
@@ -1229,7 +1234,6 @@ if(MSVC)
 else(MSVC)
     set (CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -DFC_DEBUG")
         #message(STATUS "DEBUG: ${CMAKE_CXX_FLAGS_DEBUG}")
-        message(STATUS "Build type: ${CMAKE_BUILD_TYPE}")
 endif(MSVC)
 
 if(MINGW)
@@ -1282,6 +1286,9 @@ endif(CMAKE_COMPILER_IS_GNUCXX OR MINGW)
 message(STATUS "\n==============\n"
                "Summary report\n"
                "==============\n")
+if (DEFINED CMAKE_BUILD_TYPE)
+    message(STATUS "Build type:          ${CMAKE_BUILD_TYPE}")
+endif()
 
 # Qt5 needs/sets PYTHON_CONFIG_SUFFIX regarding Shiboken
 message(STATUS "Python:              [${PYTHON_EXECUTABLE}] [${PYTHON_CONFIG_SUFFIX}]")