ar: модификатор «u» игнорируется, так как по умолчанию используется «D» (смотрите «U»)
utun_instance.c: In function ‘utun_instance_destroy’:
utun_instance.c:98:17: warning: implicit declaration of function ‘conn_destroy’; did you mean ‘uasync_destroy’? [-Wimplicit-function-declaration]
   98 |                 conn_destroy(instance->connections[i]);
      |                 ^~~~~~~~~~~~
      |                 uasync_destroy
utun_instance.c: In function ‘tun_read_callback’:
utun_instance.c:237:21: warning: implicit declaration of function ‘conn_send’ [-Wimplicit-function-declaration]
  237 |                 if (conn_send(route.next_hop, buffer, nread) < 0) {
      |                     ^~~~~~~~~
utun_instance.c: In function ‘utun_instance_unregister_sockets’:
utun_instance.c:276:57: warning: passing argument 2 of ‘uasync_remove_socket’ makes pointer from integer without a cast [-Wint-conversion]
  276 |         uasync_remove_socket(instance->ua, instance->tun.fd);
      |                                            ~~~~~~~~~~~~~^~~
      |                                                         |
      |                                                         int
In file included from utun_instance.c:8:
../lib/u_async.h:35:48: note: expected ‘void *’ but argument is of type ‘int’
   35 | err_t uasync_remove_socket(uasync_t* ua, void* s_id);
      |                                          ~~~~~~^~~~
etcp_connections.c: In function ‘etcp_link_send_init’:
etcp_connections.c:223:5: warning: implicit declaration of function ‘sc_get_public_key’; did you mean ‘sc_set_peer_public_key’? [-Wimplicit-function-declaration]
  223 |     sc_get_public_key(sc, pubkey);
      |     ^~~~~~~~~~~~~~~~~
      |     sc_set_peer_public_key
etcp_connections.c: In function ‘init_connections’:
etcp_connections.c:432:29: warning: initialization of ‘struct config *’ from incompatible pointer type ‘struct utun_config *’ [-Wincompatible-pointer-types]
  432 |     struct config* config = instance->config;
      |                             ^~~~~~~~
etcp_connections.c:433:42: error: invalid use of undefined type ‘struct config’
  433 |     instance->connections = calloc(config->server_count, sizeof(conn_handle_t*));
      |                                          ^~
etcp_connections.c:438:31: error: invalid use of undefined type ‘struct config’
  438 |     for (int i = 0; i < config->server_count; i++) {
      |                               ^~
etcp_connections.c:439:47: error: invalid use of undefined type ‘struct config’
  439 |         struct server_config* server = &config->servers[i];
      |                                               ^~
etcp_connections.c:442:30: warning: implicit declaration of function ‘parse_ip_port’ [-Wimplicit-function-declaration]
  442 |         uint16_t bind_port = parse_ip_port(server->addr, bind_ip_str, sizeof(bind_ip_str));
      |                              ^~~~~~~~~~~~~
etcp_connections.c:485:43: warning: assignment to ‘struct ETCP_SOCKET *’ from incompatible pointer type ‘struct ETCP_CONNECTIONS *’ [-Wincompatible-pointer-types]
  485 |             instance->first_listen_socket = conns;
      |                                           ^
etcp_connections.c:489:35: error: invalid use of undefined type ‘struct config’
  489 |         for (int j = 0; j < config->client_count; j++) {
      |                                   ^~
etcp_connections.c:490:51: error: invalid use of undefined type ‘struct config’
  490 |             struct client_config* client = &config->clients[j];
      |                                                   ^~
make[2]: *** [Makefile:626: utun-etcp_connections.o] Ошибка 1
make[1]: *** [Makefile:433: all-recursive] Ошибка 1
make: *** [Makefile:353: all] Ошибка 2