new darwin library patch

git diff
diff --git a/SConstruct b/SConstruct
index 09c0825..31f8c57 100644
--- a/SConstruct
+++ b/SConstruct
@@ -580,6 +580,7 @@ def VersionedSharedLibrary(env, libname, libversion, lib_objs=[], parse_flags=[]
     elif platform == 'darwin':
         ilib_suffix = '.' + libversion + shlib_suffix
         shlink_flags += [ '-current_version', '%s' % libversion,
+                          '-compatibility_version', '%s' % libversion,
                           '-undefined', 'dynamic_lookup' ]

     ilib = env.SharedLibrary(libname,lib_objs,