Require CLONE_NOOWNERCOPY to be defined for clone on mac (#694)

Fixes #688.

diff --git a/src/Util.cpp b/src/Util.cpp
index d223c19b30777f048a1c300f8a064e59a7e864b4..d95806d1840ef5e2964b738822f6436472ebbf94 100644 (file)
--- a/src/Util.cpp
+++ b/src/Util.cpp
@@ -72,7 +72,9 @@ extern "C" {
 #ifdef __APPLE__
 #  ifdef HAVE_SYS_CLONEFILE_H
 #    include <sys/clonefile.h>
-#    define FILE_CLONING_SUPPORTED 1
+#    ifdef CLONE_NOOWNERCOPY
+#      define FILE_CLONING_SUPPORTED 1
+#    endif
 #  endif
 #endif