Pipeline failing on Flutter Build due to not finding pubspec.yaml

I have setup a new project and after cloning the repo successfully, the Flutter Build task fails with error:

Error: No pubspec.yaml file found.
This command should be run from the root of your Flutter project.

The file is definitely in my repo, however, I have the feeling the problem lies in the definition of my BITRISE_FLUTTER_PROJECT_LOCATION environment variable. I set it up as / which I assumed it would mean “root” but perhaps thats the wrong value.

Any ideas?