haskell@gentoo.org Gentoo Haskell You can disable the use of the `contravariant` package using `-f-contravariant`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If disabled we will not supply instances of `Contravariant` You can disable the use of the `distributive` package using `-f-distributive`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If disabled we will not supply instances of `Distributive` You can disable the use of the `tagged` package using `-f-tagged`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. Enable the use of the `unordered-containers` package (and also its dependency `hashable`). Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. ekmett/semigroupoids