dynamic-representable-types.ts:7:7 - error SC2001: values of type '[number, (string | undefined)?]' cannot be compiled yet (supported: number, string, boolean, arrays, Maps, Sets, RegExp, read-only Date values, functions, classes, records, unions of those, and 'unknown')

  6 | const bare: any = 41;
  7 | const optTuple: [number, string?] = [1];
    |       ^~~~~~~~
  8 | console.log(arr.length, rec.width, fn(1), bare, optTuple.length);

dynamic-representable-types.ts:8:49 - error SC2004: uses of 'optTuple' inherit the blocker on its declaration

  7 | const optTuple: [number, string?] = [1];
  8 | console.log(arr.length, rec.width, fn(1), bare, optTuple.length);
    |                                                 ^~~~~~~~~~~~~~~
  9 | export const marker: number = 1;

  hint: the declaration of 'optTuple' did not compile — fix the diagnostic reported there and these sites clear with it