[ccache] ccache has issues with current Apple compilers

[Lubos Lunak]

On Saturday 31 of May 2014, Tom Lane wrote:
> I did some further experiments and concluded that ccache is in fact kind
> of broken: when I try to compile a large project with it, I get thousands
> of weird warnings that do not appear when using gcc directly (many of them
> the same kind of "unused -I argument" bleat shown above, but others are
> warnings about C constructs that I don't normally see any warnings about).
> The resulting executables seem to work, but I can't use a toolchain that's
> this noisy.  In any case, surely it's unexpected that ccache would change
> the compiler's warning behavior?

 Use CCACHE_CPP2 when using ccache with clang (see e.g. 
http://www.mail-archive.com/ccache@lists.samba.org/msg01045.html).

-- 
 Lubos Lunak