Updated file check

internal/cli/server/chains/chain.go

@@ -2,7 +2,10 @@ package chains
 
 import (
 	"encoding/json"
+	"errors"
+	"fmt"
 	"io/ioutil"
+	"os"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
@@ -21,13 +24,23 @@ var chains = map[string]*Chain{
 	"mumbai":  mumbaiTestnet,
 }
 
-func GetChain(name string) (*Chain, bool) {
-	chain, err := ImportFromFile(name)
-	if err != nil {
-		chain, ok := chains[name]
-		return chain, ok
+func GetChain(name string) (*Chain, error) {
+	var chain *Chain
+	var err error
+	if _, fileErr := os.Stat(name); fileErr == nil {
+		if chain, err = ImportFromFile(name); err != nil {
+			return nil, fmt.Errorf("error importing chain from file: %v", err)
+		}
+		return chain, nil
+	} else if errors.Is(fileErr, os.ErrNotExist) {
+		var ok bool
+		if chain, ok = chains[name]; !ok {
+			return nil, fmt.Errorf("chain %s not found", name)
+		}
+		return chain, nil
+	} else {
+		return nil, fileErr
 	}
-	return chain, true
 }
 
 func ImportFromFile(filename string) (*Chain, error) {

internal/cli/server/config.go

@@ -591,12 +591,9 @@ func readConfigFile(path string) (*Config, error) {
 }
 
 func (c *Config) loadChain() error {
-	if c.Developer.Enabled {
-		return nil
-	}
-	chain, ok := chains.GetChain(c.Chain)
-	if !ok {
-		return fmt.Errorf("chain '%s' not found", c.Chain)
+	chain, err := chains.GetChain(c.Chain)
+	if err != nil {
+		return err
 	}
 	c.chain = chain