https://src.fedoraproject.org/rpms/perl-Tk/blob/rawhide/f/perl-Tk-Avoid-using-incompatible-pointer-type-for-old_warn.patch

From c4cd966ed0997e2acb1fdcaf112c55a78ed50847 Mon Sep 17 00:00:00 2001
From: Christopher Chavez <chrischavez@gmx.us>
Date: Mon, 19 Feb 2024 14:18:43 -0600
Subject: [PATCH] Avoid using incompatible pointer type for `old_warn`

See https://github.com/eserte/perl-tk/issues/98#issuecomment-1944054296
--- a/Event/Event.xs
+++ b/Event/Event.xs
@@ -1532,7 +1532,7 @@ PROTOTYPES: DISABLE
 BOOT:
  {
 #ifdef pWARN_NONE
-  SV *old_warn = PL_curcop->cop_warnings;
+  void *old_warn = PL_curcop->cop_warnings;
   PL_curcop->cop_warnings = pWARN_NONE;
 #endif
   newXS("Tk::Event::INIT", XS_Tk__Event_INIT, file);
--- a/tkGlue.c
+++ b/tkGlue.c
@@ -5543,13 +5543,8 @@ _((pTHX))
  char *XEventMethods = "abcdfhkmopstvwxyABDEKNRSTWXY#";
  char buf[128];
  CV *cv;
-#if PERL_REVISION > 5 || (PERL_REVISION == 5 && PERL_VERSION >= 9)
-#define COP_WARNINGS_TYPE STRLEN*
-#else
-#define COP_WARNINGS_TYPE SV*
-#endif
 #ifdef pWARN_NONE
- COP_WARNINGS_TYPE old_warn = PL_curcop->cop_warnings;
+ void *old_warn = PL_curcop->cop_warnings;
  PL_curcop->cop_warnings = pWARN_NONE;
 #endif
 
-- 
2.43.0