fix(evm-trace-block): handle native tracer errors JSON-RPC errors for "debug_traceBlockByNumber". Fixes [Nibiru#2400 bug](https://github.com/NibiruChain/nibiru/issues/2400)

CHANGELOG.md

@@ -56,6 +56,7 @@ See https://github.com/dangoslen/changelog-enforcer.
 - [#2405](https://github.com/NibiruChain/nibiru/pull/2405) - chore: additional coin logos which could be used externally
 - [#2406](https://github.com/NibiruChain/nibiru/pull/2406) - chore: added monad logo svg
 - [#2407](https://github.com/NibiruChain/nibiru/pull/2407) - feat(sudo-ante): implement zero gas actors for invoking whitelisted contract
+- [#2409](https://github.com/NibiruChain/nibiru/pull/2409) - fix(evm-trace-block): handle native tracer errors JSON-RPC errors for "debug_traceBlockByNumber". Fixes [Nibiru#2400 bug](https://github.com/NibiruChain/nibiru/issues/2400)
 - [#2410](https://github.com/NibiruChain/nibiru/pull/2410) -
 feat(evm/grpc-query): Update the "/eth.evm.v1.Query/Balance" query to work with
 "0x" Ethereum hex and "nibi"-prefixed Bech32 address formats. Return no Eth

app/ante.go

@@ -47,7 +47,7 @@ func NewAnteHandlerNonEVM(
 		ante.AnteDecPreventEthereumTxMsgs{}, // reject MsgEthereumTxs
 		ante.AnteDecAuthzGuard{},            // disable certain messages in authz grant "generic"
 		authante.NewSetUpContextDecorator(),
-		ante.AnteDecSaiOracle{PublicKeepers: pk},
+		ante.AnteDecZeroGasActors{PublicKeepers: pk},
 		wasmkeeper.NewLimitSimulationGasDecorator(opts.WasmConfig.SimulationGasLimit),
 		wasmkeeper.NewCountTXDecorator(opts.TxCounterStoreKey),
 		// TODO: bug(security): Authz is unsafe. Let's include a guard to make

app/ante/fixed_gas.go

@@ -17,7 +17,7 @@ const (
 
 var (
 	_ sdk.AnteDecorator = AnteDecEnsureSinglePostPriceMessage{}
-	_ sdk.AnteDecorator = AnteDecSaiOracle{}
+	_ sdk.AnteDecorator = AnteDecZeroGasActors{}
 )
 
 // AnteDecEnsureSinglePostPriceMessage ensures that there is only one
@@ -61,22 +61,20 @@ func (anteDec AnteDecEnsureSinglePostPriceMessage) AnteHandle(
 	return next(ctx, tx, simulate)
 }
 
-// AnteDecSaiOracle checks for Wasm execute contract calls from a set of
-// known senders to the Sai oracle contract(s) and lowers gas costs using a fixed
-// gas meter.
-type AnteDecSaiOracle struct {
+// AnteDecZeroGasActors checks for Wasm execute contract calls from a set of
+// known senders to the whitelisted contract(s), giving those transactions zero
+// gas costs using a fixed gas meter.
+type AnteDecZeroGasActors struct {
 	keepers.PublicKeepers
 }
 
-func (anteDec AnteDecSaiOracle) AnteHandle(
+func (anteDec AnteDecZeroGasActors) AnteHandle(
 	ctx sdk.Context,
 	tx sdk.Tx,
 	simulate bool,
 	next sdk.AnteHandler,
 ) (newCtx sdk.Context, err error) {
-	goCtx := sdk.WrapSDKContext(ctx)
-	resp, _ := anteDec.SudoKeeper.QueryZeroGasActors(goCtx, nil)
-	zeroGasActors := resp.Actors
+	zeroGasActors := anteDec.SudoKeeper.GetZeroGasActors(ctx)
 	if len(zeroGasActors.Senders) == 0 || len(zeroGasActors.Contracts) == 0 {
 		return next(ctx, tx, simulate)
 	}

eth/rpc/rpcapi/api_debug.go

@@ -85,7 +85,8 @@ func (a *DebugAPI) TraceBlockByNumber(height rpc.BlockNumber, config *evm.TraceC
 	// Get Tendermint Block
 	resBlock, err := a.backend.TendermintBlockByNumber(height)
 	if err != nil {
-		a.logger.Debug("get block failed", "height", height, "error", err.Error())
+		err = fmt.Errorf("%s { blockHeight: %d }", err, height)
+		a.logger.Debug("get block failed", "error", err.Error())
 		return nil, err
 	}
 

eth/rpc/rpcapi/tracing.go

@@ -142,8 +142,8 @@ func (b *Backend) TraceBlock(height rpc.BlockNumber,
 	config *evm.TraceConfig,
 	block *tmrpctypes.ResultBlock,
 ) ([]*evm.TxTraceResult, error) {
-	txs := block.Block.Txs
-	txsLength := len(txs)
+	blockTxs := block.Block.Txs
+	txsLength := len(blockTxs)
 
 	if txsLength == 0 {
 		// If there are no transactions return empty array
@@ -153,10 +153,10 @@ func (b *Backend) TraceBlock(height rpc.BlockNumber,
 	txDecoder := b.clientCtx.TxConfig.TxDecoder()
 
 	var txsMessages []*evm.MsgEthereumTx
-	for i, tx := range txs {
-		decodedTx, err := txDecoder(tx)
+	for i, blockTx := range blockTxs {
+		decodedTx, err := txDecoder(blockTx)
 		if err != nil {
-			b.logger.Error("failed to decode transaction", "hash", txs[i].Hash(), "error", err.Error())
+			b.logger.Error("failed to decode transaction", "hash", blockTxs[i].Hash(), "error", err.Error())
 			continue
 		}
 

eth/rpc/rpcapi/tracing_test.go

@@ -95,6 +95,7 @@ func (s *BackendSuite) TestTraceBlock() {
 		tmBlock     *tmrpctypes.ResultBlock
 		txCount     int
 		traceConfig *evm.TraceConfig
+		wantErr     bool
 	}{
 		{
 			name:        "happy: TraceBlock, no txs, tracer: default",
@@ -124,6 +125,18 @@ func (s *BackendSuite) TestTraceBlock() {
 			txCount:     1,
 			traceConfig: traceConfigDefaultTracer(),
 		},
+		{
+			name:        "sad: TraceBlock with ultra small timeout, causing tracer to stop too early",
+			blockNumber: *s.SuccessfulTxTransfer().BlockNumberRpc,
+			tmBlock:     tmBlockWithTx,
+			txCount:     1,
+			traceConfig: func() *evm.TraceConfig {
+				cfg := traceConfigCallTracer()
+				cfg.Timeout = "1ns" // Force immediate timeout
+				return cfg
+			}(),
+			wantErr: true,
+		},
 	}
 
 	for _, tc := range testCases {
@@ -135,6 +148,10 @@ func (s *BackendSuite) TestTraceBlock() {
 					tc.traceConfig,
 					tc.tmBlock,
 				)
+				if tc.wantErr {
+					s.Require().Error(err, tc.wantErr)
+					return
+				}
 				s.Require().NoError(err)
 				resRes = append(resRes, txTraceResults)
 			}
@@ -146,7 +163,11 @@ func (s *BackendSuite) TestTraceBlock() {
 					rpc.BlockNumber(tc.tmBlock.Block.Height),
 					tc.traceConfig,
 				)
-				s.NoError(err)
+				if tc.wantErr {
+					s.Require().Error(err)
+					return
+				}
+				s.Require().NoError(err)
 
 				var txTraceResults []*evm.TxTraceResult
 				err = json.Unmarshal(resJson, &txTraceResults)

x/evm/evmstate/grpc_query.go

@@ -690,29 +690,42 @@ func (k Keeper) TraceBlock(
 		big.NewInt(ctx.BlockHeight()),
 		evm.ParseBlockTimeUnixU64(ctx),
 	)
-	txsLength := len(req.Txs)
-	results := make([]*evm.TxTraceResult, 0, txsLength)
-
-	txConfig := NewEmptyTxConfig(gethcommon.BytesToHash(ctx.HeaderHash().Bytes()))
 
+	// NOTE: Nibiru EVM uses exclusively native tracers and considers JS tracers
+	// out of scope.
+	//
+	// Geth differentiates between native tracers and JS tracers.
+	// Native tracers are the defaults like the "callTracer" and others have low
+	// overhead and return errors if any of the txs fail tracing.
+	//
+	// JS tracers (geth only) have high overhead. Tracing for them runs a
+	// parallel process that generates statesin one thread and traces txs in
+	// separate worker threads. JS tracers store tracing errors for each tx as
+	// fields of the returned trace result instead of failing the query.
+	var (
+		results  = make([]evm.TxTraceResult, len(req.Txs))
+		txConfig = NewEmptyTxConfig(gethcommon.BytesToHash(ctx.HeaderHash().Bytes()))
+		// Transaction data as an EVM message to be traced.
+		msg *core.Message
+	)
 	for i, tx := range req.Txs {
 		result := evm.TxTraceResult{}
 		ethTx := tx.AsTransaction()
 		txConfig.TxHash = ethTx.Hash()
 		txConfig.TxIndex = uint(i)
-		msg, err := core.TransactionToMessage(ethTx, signer, evmCfg.BaseFeeWei)
-		if err != nil {
-			result.Error = err.Error()
-			continue
-		}
+		// Here in "core.TransactionToMessage", the resulting msg is guaranteed
+		// not to be nil, and potential signer errors are not relevant for
+		// tracing, as this is only a query.
+		msg, _ = core.TransactionToMessage(ethTx, signer, evmCfg.BaseFeeWei)
 		traceResult, logIndex, err := k.TraceEthTxMsg(ctx, evmCfg, txConfig, *msg, req.TraceConfig, tracerConfig)
 		if err != nil {
-			result.Error = err.Error()
-		} else {
-			txConfig.LogIndex = logIndex
-			result.Result = traceResult
+			// Since Nibiru uses native tracers from geth, failure to trace any
+			// tx means block tracing fails too.
+			return nil, fmt.Errorf("trace tx error { txhash: %s, blockHeight: %d }: %w", ethTx.Hash().Hex(), ctx.BlockHeight(), err)
 		}
-		results = append(results, &result)
+		txConfig.LogIndex = logIndex
+		result.Result = traceResult
+		results[i] = result
 	}
 
 	resultData, err := json.Marshal(results)