From f129f24bd74ad7692bd345399fb9f40aa033af9f Mon Sep 17 00:00:00 2001
From: Peter Rabbitson <ribasushi@protocol.ai>
Date: Fri, 27 Mar 2020 07:57:31 +0100
Subject: [PATCH] Bring back error-prettifyer removed in f6b707d85f4

---
 core/commands/dag/dag.go | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/core/commands/dag/dag.go b/core/commands/dag/dag.go
index 4eb2283b5..08981c24f 100644
--- a/core/commands/dag/dag.go
+++ b/core/commands/dag/dag.go
@@ -332,6 +332,15 @@ The output of blocks happens in strict DAG-traversal, first-seen, order.
 			return err
 		}
 
-		return <-errCh
+		err = <-errCh
+
+		// minimal user friendliness
+		if err != nil &&
+			!node.IsOnline &&
+			err.Error() == "merkledag: not found" {
+			err = fmt.Errorf("%s (currently offline, perhaps retry after attaching to the network)", err)
+		}
+
+		return err
 	},
 }