--- a/ui/motif/toolkit.c	Thu May 28 17:45:20 2026 +0200
+++ b/ui/motif/toolkit.c	Thu May 28 18:07:00 2026 +0200
@@ -89,6 +89,9 @@
     fallback_resources = fallbackres;
 }
 
+// NOOP on most platforms, expect macos
+void ui_set_main_thread_error_msg(const char *msg) {}
+
 void ui_init(const char *appname, int argc, char **argv) { 
     application_name = appname ? strdup(appname) : NULL;
     uic_init_global_context();