On linux, when using the --make-biff function, it gives this :
[./_weidu] WeiDU version 198
[./chitin.key] 318 BIFFs, 63268 resources
[./dialog.tlk] 114913 string entries
[./_weidu] Using scripting style "BG"
ERROR: unknown resource extension []
ERROR: unknown resource extension []
[data/bg1misc.bif] will contain 10 resources totalling 1115884 bytes
segmentation fault (core dumped)