In zlog_signal, change type of size since backtrace actually returns an int.
diff --git a/lib/log.c b/lib/log.c
index 38f8ece..86b54eb 100644
--- a/lib/log.c
+++ b/lib/log.c
@@ -230,7 +230,7 @@
 #ifdef HAVE_GLIBC_BACKTRACE
   {
     void *array[20];
-    size_t size;
+    int size;
 
     size = backtrace(array,sizeof(array)/sizeof(array[0]));
     s = buf;