Return error early when instance already exists

Without the additional check, we would offer the user to edit
the template, and only then throw an error that the instance
already exists.

Fixes #2575

Signed-off-by: Jan Dubois <[email protected]>

Author: jandubois

cmd/limactl/start.go

@@ -149,7 +149,13 @@ func loadOrCreateInstance(cmd *cobra.Command, args []string, createOnly bool) (*
 	if err != nil {
 		return nil, err
 	}
-	if len(tmpl.Bytes) == 0 {
+	if len(tmpl.Bytes) > 0 {
+		if createOnly {
+			if _, err := store.Inspect(tmpl.Name); err == nil {
+				return nil, fmt.Errorf("instance %q already exists", tmpl.Name)
+			}
+		}
+	} else {
 		if arg == "" {
 			if tmpl.Name == "" {
 				tmpl.Name = DefaultInstanceName