--- a/common/log.c	2020-08-31 09:56:09.995682785 +0200
+++ b/common/log.c	2020-08-26 04:32:21.000000000 +0200
@@ -555,9 +555,10 @@
     now_t = time(&now_t);
     now = localtime(&now_t);
 
-    snprintf(buff, 21, "[%.4d%.2d%.2d-%.2d:%.2d:%.2d] ", now->tm_year + 1900,
+    if (snprintf(buff, 21, "[%.4d%.2d%.2d-%.2d:%.2d:%.2d] ", now->tm_year + 1900,
              now->tm_mon + 1, now->tm_mday, now->tm_hour, now->tm_min,
-             now->tm_sec);
+             now->tm_sec) < 0)
+        *buff = '\0';
 
     internal_log_lvl2str(lvl, buff + 20);