MacPorts on Lion: Warning: xcodebuild exists but failed to execute

When using sudo port install [pkg], it complaining:

Warning: xcodebuild exists but failed to execute
Warning: Xcode does not appear to be installed; most ports will likely fail to build.

The work around is:

1. Install Xcode 4.3 from Mac App Store
2. Install Command Line Tools for Xcode
3. Run the following commands:

   sudo /usr/bin/xcode-select -switch /Applications/Xcode.app
   sudo ln -s `which clang` /Applications/Xcode.app/Contents/Developer/usr/bin/