$ javac -version
javac 25.0.5

$ javac -cp processor/target/classes -d <tmp> Person.java Pizza.java BuilderUsageDemo.java
demo/src/main/java/com/ankurm/demo/BuilderUsageDemo.java:6: error: cannot find symbol
        Person p = new PersonBuilder()
                       ^
  symbol:   class PersonBuilder
  location: class BuilderUsageDemo
demo/src/main/java/com/ankurm/demo/BuilderUsageDemo.java:14: error: cannot find symbol
        Pizza pizza = new PizzaMaker()
                          ^
  symbol:   class PizzaMaker
  location: class BuilderUsageDemo
demo/src/main/java/com/ankurm/demo/BuilderUsageDemo.java:22: error: cannot find symbol
        System.out.println(new PersonBuilder().build());
                               ^
  symbol:   class PersonBuilder
  location: class BuilderUsageDemo
3 errors
exit=1

$ javac -Xlint:all -cp processor/target/classes -d <tmp> Person.java
exit=0  (no output at all: nothing warned that a processor was skipped)

$ javac -cp processor/target/classes -proc:full -d <tmp> Person.java Pizza.java BuilderUsageDemo.java
exit=0

$ javac -cp processor/target/classes -processorpath processor/target/classes -d <tmp> Person.java Pizza.java BuilderUsageDemo.java
exit=0