[RobertLowe]

Just a note about GCC/XCode on Lion (esp. if using homebrew):

The default GCC installed by Xcode is no longer GCC you expect it too be, it's actually a hybrid of LLVM and GCC

/usr/bin/gcc --version i686-apple-darwin11-llvm-gcc-4.2 (GCC) 4.2.1

A non-hybrid version in installed at:

/usr/bin/gcc-4.2 --version i686-apple-darwin11-gcc-4.2.1 (GCC) 4.2.1

It's a rather important change to GCC on mac, it even broke `brew install mysql` for awhile:

https://github.com/mxcl/homebrew/issues/6277

Some great hackers found out it was linking to Apple's internal pthread library.

Code-softly hackers.

[theatrus2]

It also breaks building GCC due to an LLVM issue (it gives a nice internal compiler error). It's fixed in LLVM upstream, but nothing Apple ships yet.