SDL_ttf: genexports: also detect symbols only present in the macos export file

SDL Commits
1 
From 9125d7e4659725e364f6976f183084b5d45f95b1 Mon Sep 17 00:00:00 2001
From: Anonymous Maarten <[EMAIL REDACTED]>
Date: Mon, 17 Nov 2025 21:28:19 +0100
Subject: [PATCH] genexports: also detect symbols only present in the macos
 export file

---
 src/genexports.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/genexports.py b/src/genexports.py
index a3d84267..0f48f6d3 100755
--- a/src/genexports.py
+++ b/src/genexports.py
@@ -455,7 +455,7 @@ def find_existing_proc_names(project_properties: SdlProjectSymbolProperties) ->
             macos_symbols.add(existing_func)
     logger.debug("symbols from macos exports file: %r", macos_symbols)
 
-    non_matching_symbols = versioned_symbols.difference(macos_symbols)
+    non_matching_symbols = (versioned_symbols - macos_symbols).union(macos_symbols - versioned_symbols)
     if non_matching_symbols:
         logger.error("Following symbols do not match: %r", non_matching_symbols)
         raise RuntimeError("Non-matching symbols", non_matching_symbols)