It looks like Spring Security's javadoc is being built with Java 11. This prevents a Java 8 build from linking to it with the following error:

javadoc: warning - Error fetching URL: https://docs.spring.io/spring-security/site/docs/5.5.0-M3/api/

The error isn't very clear, but it's due to a missing package-list file at https://docs.spring.io/spring-security/site/docs/5.5.0-M3/api/package-list. This is a regression from M2 where https://docs.spring.io/spring-security/site/docs/5.5.0-M2/api/package-list exists.

Until we raise the minimum supported version of Java, I think it would be preferable to use Java 8 to generate the project's javadoc to avoid this sort of problem. It would also be consistent with other Spring projects which, AFAIK, are all using Java 8 for javadoc generation at the moment.

If Java 11 has to be used, perhaps you could put a workaround in place that's similar to the one that the Gradle team used?

Comment From: wilkinsona

Thanks, @jzheaux. Did you consider switching to Java 8 so that Spring Security's javadoc is consistent with the other projects'?