Comment by kccqzy

Yup. A popular way to get proper cancellation is to build exceptions into the language and specifically async exceptions so one goroutine can throw an exception into another goroutine. And Go does not have exceptions. Doing so would require all regular Go code to be exception safe, and really requires some form of try/finally or RAII but not defer. Anyways exceptions are quite far from the Go creators’ vision of the language.