Fault

Errors can be annotated with key-value pairs via fctx, enabling seamless integration with structured logging tools and better diagnostics, as shown in the logging example with trace IDs and user IDs.

Allows wrapping errors with multiple utilities like fmsg, fctx, and ftag in a single fault.Wrap call, making error composition clean and readable without nested function calls.

fmsg.WithDesc provides distinct messages for developers and end-users, improving user experience and debugging, with GetIssue concatenating user messages for clear output.

fctx attaches context metadata to errors, ensuring traceability across call stacks, which is essential for logging in large-scale applications, as demonstrated with request-specific data.