message: Properly surface GraphQL errors in introspection error message.
  A global error helper would be better, but a properly surfaced `Error`,
  rather than a `console.error` will suffice for now.
  Feedback from:
  Ref:
diff: @@ -32,8 +32,10 @@ async function buildIntrospectionSchemaFromSDL(
  );
  if (executionResult.errors) {
  - console.error(executionResult.errors);
  - throw new Error("No data received during introspection query execution.");
  + throw new Error(
  + "An error occurred during introspection query execution.\n" +
  + executionResult.errors.map(({ message }: Error) => message).join("\n")
  + );
  }
  if (!executionResult.data) {
  