Display stack traces on error

[technomancy]

We should check for the presence of clj-stacktrace first and prefer that to the built-in stuff.

[hugoduncan]

In ritz, the clojure.lang.ExceptionData exceptions also display the map object contained in the exception. This would be nice to have in nrepl too. Not sure if that is a core, clj-stacktrace, or nrepl concern.

[Raynes]

Fake $10 reward to the person who does this issue.

[technomancy]

I have a "stacktraces" branch that implements the beginnings of this, but I realized that it's not a very good approach. I didn't realize the err handler was for output on stderr; i thought it was just triggered when an error occurred.

I think we'll need to change this so we can wrap all outgoing evals in a try/catch that uses clj-stacktrace.repl/pst+ or falls back to clojure.stacktrace/print-stack-trace if it isn't found, and then the default err-handler should just put the output in an *nREPL error* buffer. If there's a way to override clojure.main/repl's :caught function, that would be even better.

Another hiccup is that ANSI color codes currently cause the bencode implementation to choke, so we'll need to stick with monochrome stacktraces until that's addressed.

[kingtim]

nREPL will send a response with a status of "eval-error" when an exception occurs. I created a stacktrace branch which captures this event and displays a stacktrace. What do you think?

[Raynes]

It works for me. Awesome! I can totally use this now.

[kingtim]

stacktrace branch merged, which implements basic printing of stacktraces. We can handle the issues ANSI color codes and the display of the map object suggested by @hugoduncan as separate items.