On 2016-02-14 at 19:51:19 +0100, Sven Panne wrote: [...]
As stated on the Wiki, stuff in -Wcompat will often be non-actionable, so the only option I see if -Wcompat is included in -Wall will be -Wno-compat for all my projects.
This depends on what we mean by "actionable". I'm not sure I'd consider the current -Wcompat warnings to be "non-actionable". For instance, `aeson-0.11` happens to be free of -Wall -Wcompat -Wnoncanonical-monad-instances -Wnoncanonical-monadfail-instances warnings, which didn't require any CPP, see e.g. - https://github.com/bos/aeson/pull/337/files - https://github.com/bos/aeson/pull/338/files Also, as an example for a larger code-base, {Cabal,cabal-install} HEAD in Git aspire to be warning-free as well[1]; so depending on your definition, -Wcompat *is* actionable.
-Wcompat would be restricted to a few manual local builds to see where things are heading.
[1]: See .e.g. https://github.com/haskell/cabal/blob/master/Cabal/Cabal.cabal#L191-L193 if impl(ghc >= 8.0) ghc-options: -Wcompat -Wnoncanonical-monad-instances -Wnoncanonical-monadfail-instances and the Travis job enables -Werror