Compiling on Mac OS X: GSL & GSLBLAS

Hi, I been trying to compile breve on OS X for the last couple of hours, downloading, building and installing each required library from source as each "missing xxx library" message appeared. Now, the missing library seems to be GSL, but the documentation is a bit ambiguous on this point.

It lists GSL as [required] and a few lines later it lists it as [optional].

Is it required or, if not, what should I change so it continues building without it?

Further, it says this about the [required] libgslblas "On Mac OS X, the System vecLib framework is used, which provides AltiVec hardware acceleration on supported chips."

Is this a particular version or just the regular version from gnu.org?

Thanks!

(note: I'm trying to build from the nightly CVS version - breve_source_02-09-06)