error: '??' default has type 'i64', but the optional's payload is '(i32,)' (note: a 1-tuple value is written '(x,)' with a trailing comma)
  --> examples/diagnostics/1202-diagnostics-null-coalesce-tuple-default.sx:12:15
   |
12 |     x := o ?? 5; // default 'i64' vs payload '(i32,)' -> diagnostic
   |               ^