utah on phablet breaks on _save_props

I'm seeing _save_props break if I used the wrong --results-dir path:

king@lenovo:~/nexus-power/utah$ sudo PYTHONPATH=./touch ./touch/examples/run_utah_phablet.py --skip-install -l /home/phablet/examples/pm_probes.run --results-dir /home/king/nexus
= setting up network...
Network file is /etc/NetworkManager/system-connections/GLMLINUX
Provisioning network file to device
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
adbd is already running as root
6 KB/s (294 bytes in 0.041s)

Network setup complete

= installing utah...
adbd is already running as root
gpg: keyring `/tmp/tmpsr90l_/secring.gpg' created
gpg: keyring `/tmp/tmpsr90l_/pubring.gpg' created
gpg: requesting key 63840199 from hkp server keyserver.ubuntu.com
gpg: /tmp/tmpsr90l_/trustdb.gpg: trustdb created
gpg: key 63840199: public key "Launchpad PPA for Ubuntu Automation Test Harness Dev" imported
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)
OK
Reading package lists...
Building dependency tree...
Reading state information...
utah-client is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 74 not upgraded.
Traceback (most recent call last):
  File "./touch/examples/run_utah_phablet.py", line 322, in <module>
    main()
  File "./touch/examples/run_utah_phablet.py", line 316, in main
    _save_props(args)
  File "./touch/examples/run_utah_phablet.py", line 138, in _save_props
    with open(props_file, 'w') as f:
IOError: [Errno 2] No such file or directory: '/home/king/nexus/adb.props'

.. _save_props does zero error checking:

def _save_props(args):
    props = _adb(args, ['shell', 'getprop'], True)
    props_file = os.path.join(args.results_dir, 'adb.props')
    with open(props_file, 'w') as f:
        f.write(props)

Perhaps some error checking or stat'ing the directory before it's open'd would be more user friendly.