Establish controlled red-suite baseline

tests/compat/tests/social_constructor_semantics.rs

@@ -7,14 +7,14 @@ use libremetaverse::{AppearanceManager, AvatarManager, Error};
 // parity-case: LibreMetaverse.Tests/ConstructorNullArgumentTests.cs::ConstructorNullArgumentTests.AppearanceManager_Null_Throws::test a3c872805bc924b5a1a9441d5c9eb61ed6d6e9477e4bb411131359290b144ab4 translated
 #[test]
 fn appearance_manager_null_throws() {
-    assert!(matches!(
-        AppearanceManager::new(None),
-        Err(Error::ArgumentNull)
-    ));
+    assert_eq!(
+        AppearanceManager::new(None).err(),
+        Some(Error::ArgumentNull)
+    );
 }
 
 // parity-case: LibreMetaverse.Tests/ConstructorNullArgumentTests.cs::ConstructorNullArgumentTests.AvatarManager_Null_Throws::test 54f23cbf0ba87b0525c2914e78d75808e93fd1c460fc0bec4d15f09575b1431c translated
 #[test]
 fn avatar_manager_null_throws() {
-    assert!(matches!(AvatarManager::new(None), Err(Error::ArgumentNull)));
+    assert_eq!(AvatarManager::new(None).err(), Some(Error::ArgumentNull));
 }