build path path\spark either does not exist, is not accessible, or is not a valid URL. Apache Iceberg

Question

I am trying to launch the dokcer-compose.yaml for Apache Iceberg build found with instructions here:

https://iceberg.apache.org/spark-quickstart/

However when running docker-compose up -d I get the following error:

'build path path\spark either does not exist, is not accessible, or is not a valid URL'

In the compose file I can see this line :

    build: spark/

So it looks like it is trying to build an image from here?

Why does this not work considering I haven't made any changes?