Setting parse-numbers: false caused number options to become strings as well. Since we seem to have little control over positional arguments, let's make it an option instead.

lib/cli/provider/index.js

@@ -159,7 +159,8 @@ module.exports.handler = function(argv) {
       var fork = require('child_process').fork
 
       var args = [
-        'device', device.id
+        'device'
+      , '--serial', device.id
       , '--provider', argv.name
       , '--screen-port', ports.shift()
       , '--connect-port', ports.shift()