Error reporting at the REPL now categorizes errors based on their phase of execution (read, macroexpand, compile, etc). Errors carry additional information about location and context as data, and present phase-specific error messages with better location reporting. This functionality is built into the clojure.main REPL, but the functionality is also available to other REPLs and tools with the ability to use and/or modify the data to produce better error messages.