Fix panic on nil pointer in state. Add panic recover code.

cli/cli_app.go

@@ -64,7 +64,9 @@ func CreateTerragruntCli(version string) *cli.App {
 
 // The sole action for the app. It forwards all commands directly to Terraform, enforcing a few best practices along
 // the way, such as configuring remote state or acquiring a lock.
-func runApp(cliContext *cli.Context) error {
+func runApp(cliContext *cli.Context) (finalErr error) {
+	defer errors.Recover(func(cause error) { finalErr = cause })
+
 	terragruntConfig, err := config.ReadTerragruntConfig()
 	if err != nil {
 		return err

errors/errors.go

@@ -57,4 +57,16 @@ func PrintErrorWithStackTrace(err error) string {
 	case *goerrors.Error: return underlyingErr.ErrorStack()
 	default: return err.Error()
 	}
+}
+
+// A method that tries to recover from panics, and if it succeeds, calls the given onPanic function with an error that
+// explains the cause of the panic. This function should only be called from a defer statement.
+func Recover(onPanic func(cause error)) {
+	if rec := recover(); rec != nil {
+		err, isError := rec.(error)
+		if !isError {
+			err = fmt.Errorf("%v", rec)
+		}
+		onPanic(WithStackTrace(err))
+	}
 }

main.go

@@ -13,20 +13,25 @@ var VERSION string
 
 // The main entrypoint for Terragrunt
 func main() {
+	defer errors.Recover(checkForErrorsAndExit)
+
 	app := cli.CreateTerragruntCli(VERSION)
 	err := app.Run(os.Args)
 
-	if err != nil {
-		printError(err)
-		os.Exit(1)
-	}
+	checkForErrorsAndExit(err)
 }
 
-// Display the given error in the console
-func printError(err error) {
-	if os.Getenv("TERRAGRUNT_DEBUG") != "" {
-		util.Logger.Println(errors.PrintErrorWithStackTrace(err))
+// If there is an error, display it in the console and exit with a non-zero exit code. Otherwise, exit 0.
+func checkForErrorsAndExit(err error) {
+	if err == nil {
+		os.Exit(0)
 	} else {
-		util.Logger.Println(err)
+		if os.Getenv("TERRAGRUNT_DEBUG") != "" {
+			util.Logger.Println(errors.PrintErrorWithStackTrace(err))
+		} else {
+			util.Logger.Println(err)
+		}
+		os.Exit(1)
 	}
+
 }

remote/remote_state.go

@@ -55,7 +55,7 @@ func shouldConfigureRemoteState(remoteStateFromTerragruntConfig RemoteState) (bo
 		return false, err
 	}
 
-	if state.IsRemote() {
+	if state != nil && state.IsRemote() {
 		return shouldOverrideExistingRemoteState(state.Remote, remoteStateFromTerragruntConfig)
 	} else {
 		return true, nil