Using apple-gcc42 on Tiger

[Ryan Schmidt]

I see lots of revisions like r91601 being committed where the apple-gcc42 port is being used as the compiler on Tiger to work around problems with the old compilers in Tiger's Xcode.

Could this be added to the PortfileRecipes wiki page? Specifically I'm trying to figure out how to know if a particular Tiger build failure would benefit from this change -- what is(are) the signature error message(s) that would indicate apple-gcc42 should be employed?

I'm also curious why Leopards gcc-4.0 would nevertheless still be suitable. Or would it be better to just say if compiler is gcc-4.0, use gcc-4.2 or apple-gcc42?