[atombender]

In the sense that errors are values, you should not normally need to hunt for the origin of errors, and so stack traces should unnecessary.

Many errors don't need metadata. For example, io.EOF signaling the end of a stream is a normal condition. But there are those "true" errors which are unexpected conditions indicative of a bug or a scenario that should be handled differently. To make those easier to find, you can annotate the error values to make it clear what the origin was. This is why there's now a well-established convention to wrap with contextual descriptions at every point in the chain.

In about 8 years of working full-time with Go, the number of situations where I've struggled to hunt down the source of an error value is pretty close to zero. Not zero, but close.