--- VTK-8.2.0.bak/ThirdParty/libxml2/vtklibxml2/threads.c
+++ VTK-8.2.0/ThirdParty/libxml2/vtklibxml2/threads.c
@@ -49,7 +49,7 @@
 #ifdef HAVE_PTHREAD_H
 
 static int libxml_is_threaded = -1;
-#ifdef __GNUC__
+#if 0
 #ifdef linux
 #if (__GNUC__ == 3 && __GNUC_MINOR__ >= 3) || (__GNUC__ > 3)
 extern int pthread_once (pthread_once_t *__once_control,