declare print_property_callback_stack() inside NDEBUG

diff --git a/lily/grob-property.cc b/lily/grob-property.cc
index 6a8faad0c114111bbf8be09790f0ec6bf288e15f..f72a523225b4497cc9e7ea1db6dfd37fa8739c8e 100644 (file)
--- a/lily/grob-property.cc
+++ b/lily/grob-property.cc
@@ -22,9 +22,9 @@
 #include "protected-scm.hh"
 
 Protected_scm grob_property_callback_stack = SCM_EOL;
-extern bool debug_property_callbacks;
 
 #ifndef NDEBUG
+extern bool debug_property_callbacks;
 static SCM modification_callback = SCM_EOL;
 static SCM cache_callback = SCM_EOL;