11.1-PRERELEASE, waagent crashes attaching reosurce disc in Azure

[Pete French]

Have upgraded one of my Azure boxes to 11.1-PRERELEASE yesterday, and I
now find the below backtrace from waagent when it tries to attach
the resource disc. It looks as if it is finding 'pass1' as the device,
when it should be finding 'da1'. As the waagents hasnt changed I am
wondering what might have chnaged in FreeBSD to make this stop working.

I consider this to be an Azure bug not a FreeBSD bug, and have
filed an issue, but would be nice to get to the bottom of it myself.

cheers,

-pete.

2017/05/25 10:09:00.745944 INFO Activate resource disk
2017/05/25 10:09:00.788944 INFO Resource disk device pass1 found.
2017/05/25 10:09:00.794396 ERROR Event: name=WALinuxAgent, op=UnhandledError, message=Traceback (most recent call last):
File "/usr/local/lib/python2.7/site-packages/azurelinuxagent/daemon/main.py", line 77, in run
self.daemon(child_args)
File "/usr/local/lib/python2.7/site-packages/azurelinuxagent/daemon/main.py", line 117, in daemon
self.resourcedisk_handler.run()
File "/usr/local/lib/python2.7/site-packages/azurelinuxagent/daemon/resourcedisk/default.py", line 59, in run
mount_point = self.activate_resource_disk()
File "/usr/local/lib/python2.7/site-packages/azurelinuxagent/daemon/resourcedisk/default.py", line 68, in activate_resource_disk
mount_point = self.mount_resource_disk(mount_point)
File "/usr/local/lib/python2.7/site-packages/azurelinuxagent/daemon/resourcedisk/freebsd.py", line 85, in mount_resource_disk
partition_table_type = disks[device]
KeyError: u'pass1'