The source is irrelevant: the repeated warnings are the issue.

$ /opt/jdk/1.7.0/bin/javac -cp classes -source 6 -processor InjectorProc archive/PrintsSample/src/main/java/App.java
warning: [options] bootstrap class path not set in conjunction with -source 1.6
archive/PrintsSample/src/main/java/App.java:14: Note:
    public void test() {
                ^
  @SampleAnn()
  public void test() {
  }
warning: [options] bootstrap class path not set in conjunction with -source 1.6
warning: [options] bootstrap class path not set in conjunction with -source 1.6
1 warning