Hello. I'm coming with a proposal for removing transformers dependency from ghc library. The reason for this proposal that it's not possible to build consistent environment where a modern libraries (that depend on a newer transformers or mtl-2.2) and libraries that use ghc API are used together. And often people are tend to use version that is bundled with ghc, even if newer are available. As transformers usage are quite limited in ghc, and it's really relevant in ghc-bin, it's possible to duplicate the code, and provide required fixes in ghc-bin.cabal. As a result ghc uses it's own MonadIO, MonadControl and Strict State, and ghc-bin.cabal (ghc/*) uses ones from transformers. I have prepared a proof of concept [1], however it doesn't look very clean and it's quite possible that will require some generalization, for example introduction of the ghc-transformers-instances package that will have all required instances. Should I continue doing this? Are there any things to consider and fix? [1] https://github.com/qnikst/ghc/compare/wip/remove-tf -- Alexander