[tsimionescu]

Oops, I forgot if errors.New takes the 'cause' as well.

Regarding you example: the code itself still contains redundant information for someone reading it. True, the error ends up being nicer, though I would argue that the user would have been better served with a simple 'failed to load template file: /tmp/test.tpl', no need to show the pseudo call stack (so, only the fictional template loader should have been wrapping the error,for this particular case). And for a developer, the full call stack may be more useful. Exceptions would give you both for free - a nice message that can be shared to the user by whoever caused the most understandable error, and a call stack that can be logged at the upper layer so developers can see it if a bug is logged, and get a much fuller context.

[mikeschinkel]

The full call stack is available in Go but it is up to the developer if they want to include it or not which they can do by creating a custom error type and implementing that to be part of their type. And having the choice seems like a benefit to me.