shadowm@asheviere:~$ readlink -e `which wesnoth_addon_manager`
/sources/wesnoth/master/data/tools/wesnoth_addon_manager
shadowm@asheviere:~$ wesnoth_addon_manager --help
Traceback (most recent call last):
  File "/home/shadowm/bin/wesnoth_addon_manager", line 19, in <module>
    import argparse
ImportError: No module named argparse