x.go

package main 

func goRecover(f func(), recovered chan<- error) {
	go func() {
		done := false // just to handle panic(nil) https://github.com/golang/go/issues/25448
		defer func() {
			if !done {
				var errOut error
				errAny := recover()
				if err, ok := errAny.(error); ok {
					// errors.Wrap adds stacktrace to error
					errOut = errors.Wrap(err, "goRecover")
				} else {
					// errors.Errorf adds stacktrace to error
					errOut = errors.Errorf("PANIC cast to error: %v", errAny)
				}
				recovered <- errOut
			}
		}()
		f()
		done = true
	}()
}