The exact warning was:
> (goat-exercise-gjs:26895): Gjs-WARNING **: 15:59:18.382: Some code
> called array.toString() on a Uint8Array instance. Previously this
> would have interpreted the bytes of the array as a string, but that is
> nonstandard. In the future this will return the bytes as
> comma-separated digits. For the time being, the old behavior has been
> preserved, but please fix your code anyway to explicitly call
> ByteArray.toString(array).  (Note that array.toString() may have been
> called implicitly.)