GNU Make 3.82

Just noticed that this kind of constructs chokes GNU Make 3.82

     test x$CC = x && CC = gcc

It can be replaced by

     CC ?= gcc

Which can be written in a long form:

     ifeq ($(origin CC), undefined)
     CC= gcc
     endif

The other thing that is making this version of GNU Make choke are leading spaces in multi-line rules. Please, use tabs when writing Makefiles.