@arooni: Use my fork: https://github.com/NiLuJe/KindleTool
, yifan's original is known to behave strangely regarding to the CLI on some (most?) recent Linux distros.
(My best guess would be because messing with getopt's optind in a certain way or optreset seems to be a potentially unportable BSD hack
:? [Yifan's main dev platform is OS X])
Or get a static build from here
Or, as it's not an OTA2 package, use the goold old python packer