Just as one data point, the Swift compiler is by default showing warnings about upcoming changes. Just like deprecation warnings, I do find that helpful. Based on that experience, including -Wcompat in -Wall seems like a good plan to me.
Manuel > Ben Gamari <b...@well-typed.com>: > > tl;dr. GHC has a new set of warnings, -Wcompat, intended to give users > advance notice of coming library changes. We want to know whether > you think this set should be included in -Wall. See the Wiki [4] > and voice your opinion via the linked poll. > > > Hello everyone, > > GHC 8.0.1 will include a new warning group, -Wcompat, which arose out of > the MonadFail proposal discussion [1] late last year. This warning set > is intended to provide a means of informing users of coming changes in > GHC's core libraries. > > We would like to solicit the community's feedback on whether this new > flag set should be implied by -Wall. > > This proposal is motivated by concern expressed by some that -Wcompat > would see little usage unless it is placed in one of the warning sets > typically used during development. One such set is -Wall, which enables > a generous fraction of GHC's warning collectionand is is intended [2] > for use during development. > > Unfortunately, despite the (albeit only recently stated) intent of > flag, -Wall is widely used outside of development [3], often with the > expectation that the result be warning-clean across multiple GHC > versions. While we hope that -Wall will see less use in this context in > the future, given its current role we wouldn't want to add options to it > that would cause undue burden for users. > > So, we are asking for your opinion: should -Wcompat be implied by -Wall? > You can find a more thorough description of the precise proposal on the > GHC Wiki [4]. It would be very much appreciated if you could take a few > minutes familiarize yourself with the options and provide your thoughts > via this quick poll, > > > https://docs.google.com/forms/d/1BmIQvhHcnDB79LgBvaWl_xXpS1q0dMHe3Gq9JeU9odM/viewform > > Feel free to discuss the issue further in this thread. > > Thank you for sharing, > > - Ben > > > > [1] https://mail.haskell.org/pipermail/ghc-devs/2015-October/010101.html > > [2] https://mail.haskell.org/pipermail/ghc-devs/2016-January/010955.html > > [3] In a rather unscientific study, nearly half of packages on Hackage > include it in ghc-options, > > $ tar -xf ~/.cabal/packages/00-INDEX.tar > $ (for pkg in $(ls); do ls $pkg/*/*.cabal | sort -r | head -n1; done) > | xargs grep -L '\-Wall' | wc -l > 4352 > $ ls | wc -l > 9347 > > [4] https://ghc.haskell.org/trac/ghc/wiki/Design/Warnings/Wcompat > _______________________________________________ > ghc-devs mailing list > ghc-d...@haskell.org > http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users