If you’ve installed Xcode 4.3, then you may have discovered that the command line compilers are no longer available by default. I’m not sure why Apple decided to exclude them from the standard install, but they did. Fortunately, they’re easy to get back.
To install them, go to the Downloads pane in Xcode preferences; you’ll see “Command Line Tools” in the list. Simply click the install button on that entry, and 130MB later, you’ll have command line tools again.
I hope Apple eventually makes this standard again. If I have the developer tools installed, I expect to, you know, have the developer tools installed!
Gah!
S.