I'm installing clang-3.2 and it's taken more than 1.5 hours already running at 400% (all CPU threads at 100%), and 3 GB of hard drive space... Around 20 GB has been written and deleted according to Activity Monitor. What the hell is going on?
It probably just takes long time to build, it's normal for some ports to take hours to build. If you're curious, you can always locate the logfile using
By the way, you do get clang bundled with Xcode, so there is often not any need to build it yourself.