if you get an android build error like this it might just be because you moved some stuff around and left a symlink pointing to to nowhere in the src directory.

BUILD FAILED
android-sdk-linux/tools/ant/ant_rules_r3.xml:395: The following error occurred while executing this line:
/android-sdk-linux/tools/ant/ant_rules_r3.xml:209: com.android.sdklib.build.ApkCreationException: Failed to add project/src