Improve bitcoind RPC/Rest error message.

diff --git a/src/verifier.rs b/src/verifier.rs
index 5e912446d3a219ad22f8363a3b329a254f45cbb9..3d58ee0b7bab4c5349b7170692133e321383869b 100644 (file)
--- a/src/verifier.rs
+++ b/src/verifier.rs
@@ -1,4 +1,5 @@
 use std::convert::TryInto;
+use std::io::ErrorKind;
 use std::ops::Deref;
 use std::sync::Arc;
 use std::sync::Mutex;
@@ -65,7 +66,15 @@ impl<L: Deref + Clone + Send + Sync + 'static> ChainVerifier<L> where L::Target:
                let block_hash_result =
                        client.request_resource::<BinaryResponse, RestBinaryResponse>(&uri).await;
                let block_hash: Vec<u8> = block_hash_result.map_err(|error| {
-                       log_error!(logger, "Could't find block hash at height {}: {}", block_height, error.to_string());
+                       match error.kind() {
+                               ErrorKind::InvalidData => {
+                                       // the response length was likely 0
+                                       log_error!(logger, "Could't find block hash at height {}: Invalid response! Please make sure the `-rest=1` flag is set.", block_height);
+                               }
+                               _ => {
+                                       log_error!(logger, "Could't find block hash at height {}: {}", block_height, error.to_string());
+                               }
+                       }
                        UtxoLookupError::UnknownChain
                })?.0;
                let block_hash = BlockHash::from_slice(&block_hash).unwrap();