Due to a bug in Python's argument parsing library, credentials beginning with a dash (-) will throw an expected at least one argument error message. To get around this, specify the credentials by using the 'long' argument format (note the = sign):
By default CME will exit after a successful login is found. Using the --continue-on-success flag will continue spraying even after a valid password is found. Usefull for spraying a single password against a large user list.