Three points from discussion in https://github.com/reactjs/react-redux/issues/756:

* Due to https://bugs.chromium.org/p/chromium/issues/detail?id=701371, environments like CodeSandbox show `Error: null` in our “React caught an error” warning. Let’s consider skipping both as they’re not very useful and look like a bug. `Error: null` looks like a separate error and draws attention away from the real error just above.

* In any case we should probably not print `The error was thrown at:` if we don’t have a JS stack.

* There is a related issue. What do we pass to error boundary if we caught `null`? It seems that most error boundaries will intuitively do something like `if (this.state.error)` or read `error.message`, which `null` will break. There are other falsy values too like `''` and `undefined`. My proposal is we always wrap primitives into our own `Error` objects that we pass to the boundary.
invariant(
        typeof injectedErrorUtils.invokeGuardedCallback === 'function',
        'Injected invokeGuardedCallback() must be a function.',
      );
      invokeGuardedCallback = injectedErrorUtils.invokeGuardedCallback;
    },
  },
  /**
   * Call a function while guarding against errors that happens within it.
   * Returns an error if it throws, otherwise null.
   *
   * In production, this is implemented using a try-catch. The reason we don't
   * use a try-catch directly is so that we can swap out a different
   * implementation in DEV mode.
   *
   * @param {String} name of the guard to use for logging or debugging
   * @param {Function} func The function to invoke
   * @param {*} context The context to use when calling the function
   * @param {...*} args Arguments for function
   */
  invokeGuardedCallback: function<A, B, C, D, E, F, Context>(
    name: string | null,
    func: (a: A, b: B, c: C, d: D, e: E, f: F) => void,
    context: Context,
    a: A,
    b: B,
    c: C,
    d: D,
    e: E,
    f: F,