Function foreign_services 

pub fn foreign_services(
    config_text: &str,
    project_workers: &[String],
) -> Vec<(String, String)>

Interop I5 (#1972): the Service Bindings in a generated wrangler.toml whose target is none of project_workers, as (binding, worker) in binding order: the bindings to foreign Workers, by the rule bynk deploy uses. An unreadable config has none; the serve step reports it.