This used to work before https://github.com/jenkinsci/jenkins/pull/6366 :

mvn clean javadoc:javadoc install 

AbstractGroovyViewModule references generated code (taglib-interface), so it's understandable that it now fails.

Trying

mvn clean install javadoc:javadoc 

fails because of Checkstyle violations in hudson/cli/client/Messages.java (33 in recent releases, 1 in older releases)

We run javadoc:javadoc explicitly on cert.ci to ensure we do not introduce Javadoc errors that fail the release build (although the impact PR 6366 makes me think it didn't actually accomplish that before).

Filing as a bug because I think one of the invocations above should work (in particular, Checkstyle looking at generated sources seems wrong), but open to alternatives.