Improve device filtering to ignore weird devices with question mark serials.

lib/roles/provider.js

@@ -93,16 +93,24 @@ module.exports = function(options) {
   client.trackDevices().then(function(tracker) {
     log.info('Tracking devices')
 
+    // This can happen when ADB doesn't have a good connection to
+    // the device
+    function isWeirdUnusableDevice(device) {
+      return device.id === '????????????'
+    }
+
     // Helper for ignoring unwanted devices
     function filterDevice(listener) {
-      if (options.filter) {
-        return function(device) {
-          if (options.filter(device)) {
-            listener(device)
-          }
+      return function(device) {
+        if (isWeirdUnusableDevice(device)) {
+          log.warn('ADB lists a weird device: "%s"', device.id)
+          return false
         }
+        if (options.filter && !options.filter(device)) {
+          return false
+        }
+        return listener(device)
       }
-      return listener
     }
 
     // To make things easier, we're going to cheat a little, and make all