diff --git a/chain/ethereum/src/data_source.rs b/chain/ethereum/src/data_source.rs
index 709884496e8..fdfdd833045 100644
--- a/chain/ethereum/src/data_source.rs
+++ b/chain/ethereum/src/data_source.rs
@@ -854,13 +854,29 @@ impl DataSource {
                         )
                     })?;
 
+                // Details that let a subgraph developer identify and reproduce the
+                // exact on-chain call that failed to decode. Shared by both the input
+                // and the output decoding errors below.
+                let call_context = format!(
+                    "contract: {:#x}, from: {:#x}, block: #{} ({:#x}), transaction: {}, \
+                    raw input: 0x{}",
+                    call.to,
+                    call.from,
+                    call.block_number,
+                    call.block_hash,
+                    call.transaction_hash
+                        .map(|hash| format!("{:#x}", hash))
+                        .unwrap_or_else(|| "none".to_string()),
+                    hex::encode(&call.input.0),
+                );
+
                 let values = match function_abi
                     .abi_decode_input(&call.input.0[4..])
                     .with_context(|| {
                         format!(
-                            "Generating function inputs for the call {:?} failed, raw input: {}",
-                            &function_abi,
-                            hex::encode(&call.input.0)
+                            "Generating function inputs for the call {} failed, {}",
+                            function_abi.signature_with_outputs(),
+                            call_context
                         )
                     }) {
                     Ok(val) => val,
@@ -890,8 +906,10 @@ impl DataSource {
                     .abi_decode_output(&call.output.0)
                     .with_context(|| {
                         format!(
-                            "Decoding function outputs for the call {:?} failed, raw output: {}",
-                            &function_abi,
+                            "Decoding function outputs for the call {} failed, {}, \
+                            raw output: 0x{}",
+                            function_abi.signature_with_outputs(),
+                            call_context,
                             hex::encode(&call.output.0)
                         )
                     })?;
diff --git a/chain/ethereum/src/ethereum_adapter.rs b/chain/ethereum/src/ethereum_adapter.rs
index 9c85f0ac551..5f304a031f8 100644
--- a/chain/ethereum/src/ethereum_adapter.rs
+++ b/chain/ethereum/src/ethereum_adapter.rs
@@ -1528,9 +1528,9 @@ impl EthereumAdapterTrait for EthereumAdapter {
 
             trace!(logger, "eth_call";
                 "fn" => &call.function.name,
-                "address" => hex::encode(call.address),
-                "data" => hex::encode(req.encoded_call.as_ref()),
-                "block_hash" => call.block_ptr.hash_hex(),
+                "address" => format!("{:#x}", call.address),
+                "data" => format!("0x{}", hex::encode(req.encoded_call.as_ref())),
+                "block_hash" => format!("0x{}", call.block_ptr.hash_hex()),
                 "block_number" => call.block_ptr.block_number()
             );
             Ok(req)
@@ -1544,8 +1544,13 @@ impl EthereumAdapterTrait for EthereumAdapter {
             let call::Response {
                 retval,
                 source,
-                req: _,
+                req,
             } = resp;
+            // Details of the `eth_call` that failed, so that it can be reproduced by
+            // hand. Mirrors the field names used by the `eth_call` trace above.
+            let address = format!("{:#x}", req.address);
+            let data = format!("0x{}", hex::encode(req.encoded_call.as_ref()));
+            let block_hash = format!("0x{}", call.block_ptr.hash_hex());
             match retval {
                 call::Retval::Value(output) => match call.function.abi_decode_output(&output) {
                     Ok(tokens) => (Some(tokens), source),
@@ -1553,7 +1558,15 @@ impl EthereumAdapterTrait for EthereumAdapter {
                         // Decode failures are reverts. The reasoning is that if Solidity fails to
                         // decode an argument, that's a revert, so the same goes for the output.
                         let reason = format!("failed to decode output: {}", e);
-                        info!(logger, "Contract call reverted"; "reason" => reason);
+                        info!(logger, "Contract call reverted";
+                            "reason" => reason,
+                            "fn" => &call.function.name,
+                            "address" => address,
+                            "data" => data,
+                            "output" => format!("0x{}", hex::encode(&output)),
+                            "block_hash" => block_hash,
+                            "block_number" => call.block_ptr.block_number()
+                        );
                         (None, call::Source::Rpc)
                     }
                 },
@@ -1561,33 +1574,64 @@ impl EthereumAdapterTrait for EthereumAdapter {
                     // We got a `0x` response. For old Geth, this can mean a revert. It can also be
                     // that the contract actually returned an empty response. A view call is meant
                     // to return something, so we treat empty responses the same as reverts.
-                    info!(logger, "Contract call reverted"; "reason" => "empty response");
+                    info!(logger, "Contract call reverted";
+                        "reason" => "empty response",
+                        "fn" => &call.function.name,
+                        "address" => address,
+                        "data" => data,
+                        "output" => "0x",
+                        "block_hash" => block_hash,
+                        "block_number" => call.block_ptr.block_number()
+                    );
                     (None, call::Source::Rpc)
                 }
             }
         }
 
         fn log_call_error(logger: &ProviderLogger, e: &ContractCallError, call: &ContractCall) {
+            // Identify the call that failed so it can be reproduced by hand. The
+            // calldata is re-encoded here because the request may have failed before
+            // one was built; encoding errors are reported rather than propagated
+            // since this is only ever run on an error path.
+            let address = format!("{:#x}", call.address);
+            let data = match call.function.abi_encode_input(&call.args) {
+                Ok(encoded) => format!("0x{}", hex::encode(encoded)),
+                Err(e) => format!("<failed to encode: {}>", e),
+            };
+            let block_hash = format!("0x{}", call.block_ptr.hash_hex());
+            let block_number = call.block_ptr.block_number();
             match e {
                 ContractCallError::AlloyError(e) => error!(
                     logger,
                     "Ethereum node returned an error when calling function \"{}\" of contract \"{}\": {}",
                     call.function.name,
                     call.contract_name,
-                    e
+                    e;
+                    "address" => address,
+                    "data" => data,
+                    "block_hash" => block_hash,
+                    "block_number" => block_number
                 ),
                 ContractCallError::Timeout => error!(
                     logger,
                     "Ethereum node did not respond when calling function \"{}\" of contract \"{}\"",
                     call.function.name,
-                    call.contract_name
+                    call.contract_name;
+                    "address" => address,
+                    "data" => data,
+                    "block_hash" => block_hash,
+                    "block_number" => block_number
                 ),
                 _ => error!(
                     logger,
                     "Failed to call function \"{}\" of contract \"{}\": {}",
                     call.function.name,
                     call.contract_name,
-                    e
+                    e;
+                    "address" => address,
+                    "data" => data,
+                    "block_hash" => block_hash,
+                    "block_number" => block_number
                 ),
             }
         }