Any discussion that includes important information to scout for bug bounties should cover data that is routinely leaked (without issue) by web apps every day.
Low Value Data – What Doesn’t Matter
Generally Descriptive Error Messages
Although error messages can be a valid source of sensitive information that's only if, well, the message contains sensitive data. By itself, a stack trace that includes function names, exception types, and other common debugging info is not a vulnerability. The key differentiator here is: can you imagine an attack scenario using the information?