$ javac -cp jcstress-core.jar -d out -s gen PlainPublicationTest.java Payload.java   # JDK 21.0.10, no -processorpath

Note: Annotation processing is enabled because one or more processors were found
  on the class path. A future release of javac may disable annotation processing
  unless at least one processor is specified by name (-processor), or a search
  path is specified (--processor-path, --processor-module-path), or annotation
  processing is enabled explicitly (-proc:only, -proc:full).
  Use -Xlint:-options to suppress this message.
  Use -proc:none to disable annotation processing.

$ find gen -type f
gen/com/ankurm/jmm/PlainPublicationTest_jcstress.java

$ javac -cp jcstress-core.jar -d out -s gen PlainPublicationTest.java Payload.java   # JDK 25.0.4.1+1, no -processorpath

(no output at all - exit code 0)

$ find gen -type f
(nothing - the processor was never invoked, no error, no warning)