How do I find information about variants?

[Markus Weimer]

Hi,

I am thinking about installing gcc42 using MacPorts. The Port has
three variants: universal, darwin_8 and odcctools. However, I cannot
find documentation on these variants.

I would be especially interested in whether or not any of the variants
makes the compiler usable as a drop-in replacement for apple's gcc, as
in "is able to link to system framework".

Thanks in advance,

Markus