The Haskell Playground now support GHC 9.6. You can now preview future extensions like TypeData and the new error codes

[Kleidukos]

You can now experiment with the next GHC 9.6 release!

For example: Haskell Playground

[hasufell]

It seems error GHC-83865 doesn’t have documentation yet: https://errors.haskell.org/messages/GHC-83865/index.html