I am trying to use the SimpleChrome instructions to update the build on my veyron_mickey.  However the 'cros flash' command is failing with an error.  It is trying to create a temporary directory under third_party/chroot/tmp, however, I don't have a third_party/chroot directory in my code tree.   Do I just need to make this directory by hand?

[mfoltz@sebastian /usr/local/google/home/mfoltz/chromeos/src]$ cd ../images/
[mfoltz@sebastian /usr/local/google/home/mfoltz/chromeos/images]$ cros flash --debug 100.127.70.76 chromiumos_test_image.bin
10:31:41: DEBUG: Configured cache_dir to '/media/ssd/mfoltz/chromeos/src/build/cros_cache'
10:31:41: NOTICE: Preparing to update the remote device 100.127.70.76
10:31:41: INFO: RunCommand: ping -c 1 -w 20 100.127.70.76
10:31:41: INFO: Using image chromiumos_test_image.bin
10:31:41: ERROR: Unable to get payloads from local path: /tmp/cros-flashrkyfjF
10:31:41: ERROR: Device update failed.
10:31:41: DEBUG: RunCommand: ssh -p 22 '-oConnectionAttempts=4' '-oUserKnownHostsFile=/dev/null' '-oProtocol=2' '-oConnectTimeout=30' '-oServerAliveCountMax=3' '-oStrictHostKeyChecking=no' '-oServerAliveInterval=10' '-oNumberOfPasswordPrompts=0' '-oIdentitiesOnly=yes' -i /tmp/ssh-tmpii7Ggi/testing_rsa root@100.127.70.76 -- cat /etc/lsb-release
10:31:43: INFO: Following are the LSB version details of the device:
CHROMEOS_AUSERVER=https://tools.google.com/service/update2
CHROMEOS_BOARD_APPID={181B8BE1-07A0-4D54-87B7-0157A4322FF1}
CHROMEOS_CANARY_APPID={90F229CE-83E2-4FAF-8479-E368A34938B1}
CHROMEOS_DEVSERVER=
CHROMEOS_RELEASE_APPID={181B8BE1-07A0-4D54-87B7-0157A4322FF1}
CHROMEOS_RELEASE_BOARD=veyron_mickey
CHROMEOS_RELEASE_BRANCH_NUMBER=0
CHROMEOS_RELEASE_BUILDER_PATH=veyron_mickey-release/R69-10818.0.0
CHROMEOS_RELEASE_BUILD_NUMBER=10818
CHROMEOS_RELEASE_BUILD_TYPE=Official Build
CHROMEOS_RELEASE_CHROME_MILESTONE=69
CHROMEOS_RELEASE_DESCRIPTION=10818.0.0 (Official Build) dev-channel veyron_mickey test
CHROMEOS_RELEASE_NAME=Chrome OS
CHROMEOS_RELEASE_PATCH_NUMBER=0
CHROMEOS_RELEASE_TRACK=testimage-channel
CHROMEOS_RELEASE_VERSION=10818.0.0
DEVICETYPE=CHROMEBIT
GOOGLE_RELEASE=10818.0.0
10:31:43: INFO: You can find the log files and/or payloads in /tmp/cros-flashrkyfjF
10:31:43: ERROR: cros flash failed before completing.
cros: Unhandled exception:
Traceback (most recent call last):
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/bin/cros", line 169, in <module>
    DoMain()
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/bin/cros", line 165, in DoMain
    commandline.ScriptWrapperMain(FindTarget)
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/lib/commandline.py", line 912, in ScriptWrapperMain
    ret = target(argv[1:])
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/scripts/cros.py", line 66, in main
    code = _RunSubCommand(subcommand)
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/scripts/cros.py", line 51, in _RunSubCommand
    return subcommand.Run()
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/cli/cros/cros_flash.py", line 161, in Run
    send_payload_in_parallel=self.options.send_payload_in_parallel)
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/cli/flash.py", line 569, in Flash
    updater.Run()
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/cli/flash.py", line 455, in Run
    payload_dir = self.GetPayloadDir(device)
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/cli/flash.py", line 403, in GetPayloadDir
    static_dir=DEVSERVER_STATIC_DIR)
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/lib/dev_server_wrapper.py", line 238, in GetUpdatePayloadsFromLocalPath
    static_dir=static_dir)
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/lib/dev_server_wrapper.py", line 230, in GetUpdatePayloadsFromLocalPath
    prefix='dev_server_wrapper_local_image', sudo_rm=True)
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/lib/cros_build_lib.py", line 1311, in Add
    obj = functor(*args, **kwargs)
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/lib/osutils.py", line 664, in __init__
    _TempDirSetup(self, **kwargs)
  File "/media/ssd/mfoltz/chromeos/src/third_party/chromite/lib/osutils.py", line 611, in _TempDirSetup
    self.tempdir = tempfile.mkdtemp(prefix=prefix, dir=base_dir)
  File "/usr/lib/python2.7/tempfile.py", line 339, in mkdtemp
    _os.mkdir(file, 0700)
OSError: [Errno 2] No such file or directory: '/media/ssd/mfoltz/chromeos/src/third_party/chroot/tmp/dev_server_wrapper_local_imageOgirUp'