"error: unable to resolve comptime value" on @cImport library

fu3x11 · April 2, 2025, 11:54pm

/home/user/Misc/repos/Zig/pong/.zig-cache/o/14605617d31c64870f61100d6e6b13e9/cimport.zig:4988:27: error: unable to resolve comptime value
pub const ENET_HOST_ANY = in6addr_any;

is what i got after attempting to use

github.com/leyloe/pong

src/server.zig

51fed5afa


      
                  .server = undefined,
                  .address = undefined,
              };
          }
          
          pub fn bind(self: *Self) ServerError!void {
              if (en.enet_initialize() != en.EXIT_SUCCESS) {
                  return ServerError.InitFailure;
              }
          
              self.address.host = en.ENET_HOST_ANY;
              self.address.port = self.port;
          
              self.server = en.enet_host_create(&self.address, 1, 1, 0, 0);
              if (self.server == null) {
                  return ServerError.ServerNull;
              }
          }
          
          pub fn deinit(self: Self) void {
              defer en.enet_deinitialize();

the only way i seemed to fix it was setting self.address.host to in6addr_any instead of ENET_HOST_ANY. but that seems unconventional.

here is the original c definition:

github.com/zpl-c/enet

include/enet.h

90471c702


      
          #define ENET_MIN(x, y) ((x) < (y) ? (x) : (y))
          #define ENET_DIFFERENCE(x, y) ((x) < (y) ? (y) - (x) : (x) - (y))
          
          #define ENET_IPV6           1
          static const struct in6_addr enet_v4_anyaddr   = {{{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 }}};
          static const struct in6_addr enet_v4_noaddr    = {{{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }}};
          static const struct in6_addr enet_v4_localhost = {{{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x01 }}};
          static const struct in6_addr enet_v6_anyaddr   = {{{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }}};
          static const struct in6_addr enet_v6_noaddr    = {{{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }}};
          static const struct in6_addr enet_v6_localhost = {{{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }}};
          #define ENET_HOST_ANY       in6addr_any
          #define ENET_HOST_BROADCAST 0xFFFFFFFFU
          #define ENET_PORT_ANY       0
          
          #ifdef __cplusplus
          extern "C" {
          #endif
          
          // =======================================================================//
          // !
          // ! Basic stuff

and it translates to pub const ENET_HOST_ANY = in6addr_any;

yataro · April 3, 2025, 1:03am

in6addr_any is an extern value, so It can’t be assigned to comptime constant like Zig translated it (pub const ENET_HOST_ANY = in6addr_any;). It is a translate-c bug.

I think it can be translated as:

pub const ENET_HOST_ANY = @extern(*struct_in6_addr, .{ .name = "in6addr_any" });

but this will make it a pointer, not a direct equivalent.

I propose you report this bug at Zig GitHub, if it’s not reported already.

EDIT: it was reported at translate-c: error when accessing extern variable with macro · Issue #22688 · ziglang/zig · GitHub