From 9b58fa773ad4487069bb40021264ff32738d8a0a Mon Sep 17 00:00:00 2001
From: Kevin Atkinson <k@kevina.org>
Date: Fri, 24 Mar 2017 16:18:20 -0400
Subject: [PATCH] merkledag: provide better diagnostics when Prefix.Sum fails

License: MIT
Signed-off-by: Kevin Atkinson <k@kevina.org>
---
 merkledag/node.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/merkledag/node.go b/merkledag/node.go
index 0b11b928e..ce075726d 100644
--- a/merkledag/node.go
+++ b/merkledag/node.go
@@ -266,6 +266,7 @@ func (n *ProtoNode) Cid() *cid.Cid {
 	c, err := n.Prefix.Sum(n.RawData())
 	if err != nil {
 		// programmer error
+		err = fmt.Errorf("invalid CID of length %d: %x: %v", len(n.RawData()), n.RawData(), err)
 		panic(err)
 	}