- GHCJS 8.10, exposed via `haskell.compiler.ghcjs` and `haskell.compiler.ghcjs810`, has been removed. Downstream users should migrate their projects to the new JavaScript backend of GHC proper which can be used via `pkgsCross.ghcjs` from Nixpkgs. Haskell packaging code, like `haskellPackages.mkDerivation`, `ghcWithPackages` and `hoogleWithPackages`, also no longer supports GHCJS.
- GHC 8.6, 8.10, 9.0, and their package sets have been removed.
- GHC 8.6, 8.10, 9.0, 9.2, and their package sets have been removed.
- Support for bootstrapping native GHC compilers on 32‐bit ARM and little‐endian 64‐bit PowerPC has been dropped.