$ evic-usb dump-dataflash
Finding device...OK
	Manufacturer: Nuvoton
	Product: HID Transfer
	Serial No: A02014090304

Reading data flash...OK
	Device name: eVic-VTC Mini
	Firmware version: 3.02
	Hardware version: 1.03

Writing data flash to the file...Traceback (most recent call last):
  File "/usr/local/bin/evic-usb", line 9, in <module>
    load_entry_point('evic==0.1', 'console_scripts', 'evic-usb')()
  File "/usr/local/lib/python2.7/dist-packages/click-6.2-py2.7.egg/click/core.py", line 716, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/click-6.2-py2.7.egg/click/core.py", line 696, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python2.7/dist-packages/click-6.2-py2.7.egg/click/core.py", line 1060, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python2.7/dist-packages/click-6.2-py2.7.egg/click/core.py", line 889, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python2.7/dist-packages/click-6.2-py2.7.egg/click/core.py", line 534, in invoke
    return callback(*args, **kwargs)
  File "build/bdist.linux-x86_64/egg/evic/cli.py", line 317, in dumpdataflash
AttributeError: 'NoneType' object has no attribute 'write'