autopilot3 crashed with TypeError in decode(): 'NoneType' does not support the buffer interface

Found the crash file in clock-app autopilot test results on the dasboard. The tests are failing because autopilot is not able to find the proxy object for the process. Perhaps this crash is the cause.

http://ci.ubuntu.com/smokeng/utopic/touch/mako/264:20141001:20140929.1/10758/ubuntu_clock_app/

ProblemType: Crash
DistroRelease: Ubuntu 14.10
Package: python3-autopilot 1.5.0+14.10.20140812-0ubuntu1
Uname: Linux 3.4.0-5-mako armv7l
ApportVersion: 2.14.7-0ubuntu2
Architecture: armhf
Date: Wed Oct 1 05:06:24 2014
ExecutablePath: /usr/bin/autopilot3
InstallationDate: Installed on 2014-10-01 (0 days ago)
InstallationMedia: Ubuntu Utopic Unicorn (development branch) - armhf (20141001-020204)
InterpreterPath: /usr/bin/python3.4
PackageArchitecture: all
ProcCmdline: /usr/bin/python3 /usr/bin/autopilot3 run -v --timeout-profile=long -o /tmp/test_results.subunit -f subunit ubuntu_clock_app
PythonArgs: ['/usr/bin/autopilot3', 'run', '-v', '--timeout-profile=long', '-o', '/tmp/test_results.subunit', '-f', 'subunit', 'ubuntu_clock_app']
SourcePackage: autopilot
Title: autopilot3 crashed with TypeError in decode(): 'NoneType' does not support the buffer interface
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm autopilot cdrom dialout dip plugdev sudo tty video