Save invalid block to temp save-invalid-block-temp (#13722)

config/features/config.go

@@ -72,6 +72,9 @@ type Flags struct {
 	PrepareAllPayloads bool // PrepareAllPayloads informs the engine to prepare a block on every slot.
 	// BlobSaveFsync requires blob saving to block on fsync to ensure blobs are durably persisted before passing DA.
 	BlobSaveFsync bool
+
+	SaveInvalidBlock bool // SaveInvalidBlock saves invalid block to temp.
+
 	// KeystoreImportDebounceInterval specifies the time duration the validator waits to reload new keys if they have
 	// changed on disk. This feature is for advanced use cases only.
 	KeystoreImportDebounceInterval time.Duration
@@ -187,6 +190,11 @@ func ConfigureBeaconChain(ctx *cli.Context) error {
 		cfg.WriteSSZStateTransitions = true
 	}
 
+	if ctx.Bool(saveInvalidBlockTempFlag.Name) {
+		logEnabled(saveInvalidBlockTempFlag)
+		cfg.SaveInvalidBlock = true
+	}
+
 	if ctx.IsSet(disableGRPCConnectionLogging.Name) {
 		logDisabled(disableGRPCConnectionLogging)
 		cfg.DisableGRPCConnectionLogs = true

config/features/flags.go

@@ -42,6 +42,10 @@ var (
 		Name:  "interop-write-ssz-state-transitions",
 		Usage: "Writes SSZ states to disk after attempted state transitio.",
 	}
+	saveInvalidBlockTempFlag = &cli.BoolFlag{
+		Name:  "save-invalid-block-temp",
+		Usage: "Writes invalid blocks to temp directory.",
+	}
 	disableGRPCConnectionLogging = &cli.BoolFlag{
 		Name:  "disable-grpc-connection-logging",
 		Usage: "Disables displaying logs for newly connected grpc clients.",
@@ -196,6 +200,7 @@ var BeaconChainFlags = append(deprecatedBeaconFlags, append(deprecatedFlags, []c
 	devModeFlag,
 	enableExperimentalState,
 	writeSSZStateTransitionsFlag,
+	saveInvalidBlockTempFlag,
 	disableGRPCConnectionLogging,
 	HoleskyTestnet,
 	PraterTestnet,