anchor.diff:  The output path shows that tundra has defaulted the variant to `debug` and the
   subvariant to `default`.
   
  +[source, sh]
   -------------------------------------------------------------------------------
   $ tundra2
   Cc hello.c
  
positive.code: for the unit tests, which must be made available via the Git submodule
  mechanism:
  
  -------------------------------------------------------------------------------
  $ git submodule init
  $ git submodule update
  
negative.code: 
  The next mandatory step is of course to display the famous greeting:
  
  [source, sh]
  -------------------------------------------------------------------------------
  $ t2-output/macosx-gcc-debug-default/HelloWorld
  hello, world
  