Self-hosted: Apollo Federation: Unable to use schema with @external

[yogeshcbsi]

I have been trying to host schema created with Apollo Federation into self hosted Hive but seems like Hive is not composing super-graph correctly when @external is used in schema. Super-graph schema cannot used due to this issue

Example: Schema defined in subgraph1 sub-graph as below:

name: String! @external

Results in subgraph2 sub-graph schema:

name: String! @join__field(graph: SUBGRAPH2)

Expecting it to be resulted in below supergraph schema:

name: String! @join__field(graph: SUBGRAPH2) @join__field(graph: SUBGRAPH1, external: true)

This is field is implemented as part of interface in both subgraphs.

[kamilkisiela]

I feel like I need a small reproduction here (SDLs), I can't tell if it's an issue or not based only on informations provided by you.
I don't know how you implement an interface, I don't know if an interface has a @key directive, and if so what fields are part of it etc. There's a lot of missing things here for me to verify it.