2to3 cannot detect use of `print` in command line spawned via
subprocess.Popen. To avoid confusion force the use of print_function
everwhere by adding:
from __future__ import print_function
Change-Id: Ia18eb4e6fbe0ca042661382a93959f06768317ff
All E3Error supports at least two parameters: origin and message.
origin can be set to provide more information on the "origin" of the
exception, e.g. the function name, class name, or module name.
Change-Id: I36efe1a678cc82ab742edb8799e1ac324660dcb0
