Messages and stack traces in the error are orthogonal to errors-as-values vs. exceptions for control flow. You could have `throw Exception("error fooing the bar

Messages and stack traces in the error are orthogonal to errors-as-values vs. exceptions for control flow. You could have `throw Exception("error fooing the bar", ctx)`. You could also `return error("error fooing the bar", ctx, stacktrace())`. Stack traces are also occasionally useful but not really necessary most of the time IME. Go's error handling is annoying because it requires boilerplate to make structured errors and gives you string formatting as the default path for easy-to-create error values. And the whole using a product instead of a sum thing of course. And no good story for exception-like behavior across goroutines. And you still need to deal with panics anyway for things like nil pointers or invalid array offsets.