I've been porting Burp (a backup program) to FreeBSD.
Looking at the various configure checks for detecting extended attribute support, I noticed that the declarations for extattr_namespace_to_string and extattr_string_to_namespace are in libutil.h. The functions themselves moved to libc from libutil about 10 years ago.
NetBSD has these prototypes in sys/extattr.h. Would it make sense to move them there as well?