[CentOS] CentOS7 kickstart question

Is it not possible to use an nfs based repo for kickstart under CentOS 7.5?

E.g.

repo --name=epel --baseurl=file://server/path/to/local/copy/of/epel

With trial and error I figured out that this is the correct syntax to use for an nfs-based repo. But packages from this repo in the %packages section are not found.

You have specificed that the package 'bla' should be installed. This package does not exist. ...

It works with http off the same server and location, but I'd rather not use that.

NFS installation as such, using nfs --server ... -- dir ..., off the same server and filesystem is working fine. So there is no problem here with nfs or repo setup.