Function wbcGetgrlist(declared in nsswitch/libwbclient/wbclient.h) returns an empty group list. Here is the description of the function: /** * @brief Return the next struct group* entry from the pwent iterator * * This is similar to #wbcGetgrent, just that the member list is empty * * @param **grp Pointer to resulting struct group* from the query. * * @return #wbcErr **/ wbcErr wbcGetgrlist(struct group **grp); However, in nsswitch/winbind_struct_protocol.h, the corresponding implement is: /* this is like GETGRENT but gives an empty group list */ WINBINDD_GETGRLST,