I just suffered through this for a good part of an afternoon, so figured I’d blog it for anybody else. Apparently a bunch of stuff moved around between some versions of Android, so make soft links to:
./sdk/tools/aapt to ./sdk/build-tools/17.0.0/aapt
./sdk/tools/dx to ./sdk/build-tools/17.0.0/dx
./sdk/tools/lib/dx.jar to ./sdk/build-tools/17.0.0/lib/dx.jar
So, if you’re in your ./sdk/tools directory, you can:
ln -s aapt ../build-tools/17.0.0/aapt
ln -s dx ../sdk/build-tools/17.0.0/dx
ln -s lib/dx.jar ../build-tools/17.0.0/lib/dx.jar