Yet another problem with GraphQL Playground: We've got a https://github.com/neelance/graphql-go server running, and there is a special HTTP endpoint /debug which is dev-build-only, it skips permissions and allows to do basically everything on the API. On startup I get the following error when connecting to http://localhost:8080/debug/

Introspection must provide input type for arguments.

Queries do work fine, but there's no schema docs available, the schema introspection doesn't work. Just googled the error and didn't find anything useful... any ideas what this might be caused by? Did the GQL standard change? Is it the library's fault? Or is it mine?