Comparing recent jenkins-core.jar files, https://github.com/jenkinsci/stapler/blob/a95221851a23a5405656df6063e080a9b42ec4b2/core/src/main/java/org/kohsuke/stapler/jsr269/QueryParameterAnnotationProcessor.java does not seem to reliably generate .stapler files. See attached comparison of "orphan" files (present on one side, missing on the other).