Is it GCC is it gcc, is it????

(cherry picked from commit ef2bff6383b16385f9874e1c9c6b66c9df794f5b)

src/Makefile.cfg

@@ -48,7 +48,9 @@ endif
 
 # Automatically set version flag, but not if one was manually set
 ifeq   (,$(filter GCC%,$(.VARIABLES)))
- ifneq (,$(findstring gcc,$(shell $(CC) --version))) # if it's GCC
+ version:=$(shell $(CC) --version)
+ # check if this is in fact GCC
+ ifneq (,$(or $(findstring gcc,$(version)),$(findstring GCC,$(version))))
   version:=$(shell $(CC) -dumpversion)
 
   # Turn version into words of major, minor