fontgen issues

[norayr]

hello, i don't quite understand how to use fontgen.py.

inky@ohmu ~/pebble-dev/elbbep/pebblesdk $ python2 fontgen.py 
Traceback (most recent call last):
  File "fontgen.py", line 682, in <module>
    main()
  File "fontgen.py", line 675, in main
    process_all_fonts()
  File "fontgen.py", line 615, in process_all_fonts
    f = open(os.path.join(font_directory, 'fonts.h'), 'w')
IOError: [Errno 2] No such file or directory: 'ttf/fonts.h'

i would like to generate my custom pebble font.
i don't need translations, only to change the font.
any help or hint appreciated.
thank you.