It depends on what your definition of "fundamental problem" is. If being able to treat a value differently than it was received, or to perform computations that

It depends on what your definition of "fundamental problem" is. If being able to treat a value differently than it was received, or to perform computations that you shouldn't be able to, e.g. impure actions inside a pure function, then very few languages satisfy that property. Even Haskell isn't safe because of unsafePerformIO--you'd need Safe Haskell, at the very least. Go has never tried to be, and the authors have never tried to give people the impression that it is that kind of language. Some of the safety comes from the language e.g. doing array bounds checking, not letting you manipulate memory manually, etc., but the rest comes from discipline and idiomatic code. (Same thing as not using 'undefined', 'fromJust', 'unsafePerformIO', etc. in Haskell unless you're absolutely sure they won't do harm--they are too useful to remove, even if they are the sources of many headaches.)