sorry, hit the send key too early.
* Ralf Wildenhues wrote on Sun, May 24, 2009 at 03:20:04PM CEST:
> IRIX make barfs if the inner macro expansion is used without $() or ${}
> even for one-character macros. IOW, IRIX make barfs over $(foo$V) but
> copes with $(foo$(V)).
There are also some make implementations that barf over a macro
expansion recursion depth greater than 2, i.e., $(foo$(bar$(baz)))
is not portable either. Dunno if there are situations in which that
functionality cannot be emulated through repeataed depth 2 recursion.