I gave an example in the post, but to spell it out: Because a typo variable is not caught, e.g. as an unused variable.
The example from the blog post would fail, because `return err` referred to an `err` that was no longer in scope. It would syntactically prevent accidentally writing `foo99()` instead of `err := foo99()`.
I gave an example in the post, but to spell it out: Because a typo variable is not caught, e.g. as an unused variable.
The example from the blog post would fail, because `return err` referred to an `err` that was no longer in scope. It would syntactically prevent accidentally writing `foo99()` instead of `err := foo99()`.