tsshd: fix tests on Darwin (#481262)

pkgs/by-name/ts/tsshd/package.nix

@@ -2,6 +2,7 @@
   lib,
   buildGoModule,
   fetchFromGitHub,
+  stdenv,
   versionCheckHook,
   nix-update-script,
 }:
@@ -24,6 +25,23 @@ buildGoModule (finalAttrs: {
     "-w"
   ];
 
+  # Enable for upstream KCP and QUIC tests which require UDP binding on localhost
+  __darwinAllowLocalNetworking = true;
+
+  checkFlags =
+    let
+      skippedTests = [
+        # `quic.DialAddr` of `quic-go` invokes UDP writing with `sendmsg` from address `[::]`,
+        # causing these tests to fail even with the `__darwinAllowLocalNetworking` flag enabled.
+        "TestQUIC_InitialPacketSize"
+        "TestQUIC_RespectMTU"
+        "TestQUIC_CertValidation"
+      ];
+    in
+    lib.optionals stdenv.hostPlatform.isDarwin [
+      "-skip=^${builtins.concatStringsSep "$|^" skippedTests}$"
+    ];
+
   doInstallCheck = true;
   nativeCheckInputs = [
     versionCheckHook