Comment 2 for bug 736058

during configure I see:

checking for LIBNL2... yes
checking for LIBNL1... no
configure: creating ./config.status

build succeeds.

dpkg -l libnl2-dev on maverick
ii libnl2-dev 1.99+git20091216-2 development library and headers for libnl2

which could mean that API changed after 1.99

and in netlink/cache.h I have:
extern int nl_cache_mngr_add(struct nl_cache_mngr *,
                                                  const char *,
                                                  change_func_t,
                                                  struct nl_cache **);

checking in final 2.0 and current git master, your signature seems to be right.

Unfortunately, I saw that debian updated to final 2.0 without bumping package soname. That's bad. Anyway, let me poke this a bit once I have sorted this packaging problem.; but from what I see its a data field. passing a 0 pointer in the macro as parameter position 3 might be fine for you.