How to exclude particular Dart files while compilation in flutter

Question

I'm trying to run my flutter-app in web. So I created a web folder and added all the necessary things. Since I'm using the objectBox in multiple dart files, I'm getting error based on ObjectBox. So what I did to find the issue was, In the main.dart file i'm just trying to display only simple Container widget containing a text. But still I'm getting the same error related to objectBox with its entity.

So my doubt is, Is it compiling all the dart files located in lib? If then, can I exclude them.

I have tried(created a build.yaml file) to exclude all my files which are using ObjectBox.

My build.yaml file:

targets:
  $default:
    sources:
      exclude:
        - lib/test_driver/runner.dart
        - lib/tools/**.dart