Error thrown when username is not registered

[patrickdevivo]

Using this via: https://github.com/oortcloud/node-ddp-client and if I try to authenticate to a Meteor DDP server with a username that doesn't exist, execution halts and an error is thrown:

...node_modules/ddp/node_modules/node-srp/lib/srp.js:122
    self.identity = challenge.identity;
                             ^
TypeError: Cannot read property 'identity' of undefined

is there any way of cleaning this up?

Thanks!