To: ghc-devs Cc: some plugin authors I'm aware of Today, I finally added a test that caused the type checker plugin I'm developing to fail because I'm ignoring the incoming Derived constraints. While investigating what exactly I should do with incoming Deriveds, I wrote up my notes in hopes they are helpful to other type checker plugin authors. https://gitlab.haskell.org/ghc/ghc/wikis/plugins/type-checker/notes It's a high-level summary of what the GHC constraint solver is doing, that dips down into the details a bit regarding Deriveds. I would really appreciate it if you'd check that page for errors andr glaring omissions. Also, is there a better location for it? It seemed too sprawling for a source `Note`. Thank you for your time. -Nick