From de9f84d080d358e6292e220b8fc0cc467745972f Mon Sep 17 00:00:00 2001
From: dmiller <dmiller@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Wed, 28 Sep 2022 21:40:57 +0000
Subject: [PATCH] Get better error message. See #2179

---
 libnetutil/netutil.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libnetutil/netutil.cc b/libnetutil/netutil.cc
index 56757e236..85afde390 100644
--- a/libnetutil/netutil.cc
+++ b/libnetutil/netutil.cc
@@ -3194,7 +3194,8 @@ static int route_dst_netlink(const struct sockaddr_storage *dst,
 
       intf_index = *(int *) RTA_DATA(rtattr);
       p = if_indextoname(intf_index, namebuf);
-      assert(p != NULL);
+      if (p == NULL)
+        netutil_fatal("%s: if_indextoname(%d) failed: %d (%s)", __func__, intf_index, errno, strerror(errno));
       ii = getInterfaceByName(namebuf, dst->ss_family);
       if (ii == NULL)
         ii = getInterfaceByName(namebuf, AF_UNSPEC);