The current detection of devices for build.sh looks to see if there are any serial numbers available though system_profiler SPUSBDataType. This works well enough in our testing system as they are VMWare VMs, but on a real machine there are usually serial number entries for many devices in the tree, including internal USB hubs, keyboards, mice, etc... So the results from that code is either confused or wrong. Additionally the script will try to run Xcode for all of those devices, producing bad results for most of them.

The best way to do this is probably going to be to separate that code into a second script written in Python (that includes plist parsing utilities by default), and then use the system_profiler SPUSBDataType -xml and recursively iterate through the tree to find the proper devices, and then return their serial numbers. We do have some ruby code that already does this in another repository, but would need to bring along the plist module, and that feels a little heavyweight for this purpose.