This issue is created after this comment to a PR, https://github.com/openjdk/jdk18/pull/44#pullrequestreview-835511533:

"Please file a followup bug for a more comprehensive cleanup to protect against errors in user code, like (untrusted) user-provided taglets and doclets. While this could be loosely modeled on javac ClientCodeWrapper and ClientCodeException, this time round it might be reasonable to use a Proxy-based wrapper, to catch exceptions in user-code and then throw them in a wrapped exception for better handling at a higher level. That suggests that going forward, failure to init a taglet should be a fatal error. Note: one potential complication for javadoc not found in javac is the hard tool-to-doclet abstraction barrier."