@apollo/subgraph 2.15.0 removed the legacy buildSubgraphSchema input shape and bit.cloud users got backend-server error when running the installation process, explication and our fix.

A minor version bump broke GraphQL servers this week @apollo/subgraph@2.15.0 is a ground-up reimplementation on graphql-js and it removed the legacy input shape of buildSubgraphSchema.
Full explication of bit.cloud fix for users application
https://www.reddit.com/r/bit_dev/s/SYFDV4YmdB