{"action":"created","issue":{"url":"https://api.github.com/repos/ndmitchell/hlint/issues/215","repository_url":"https://api.github.com/repos/ndmitchell/hlint","labels_url":"https://api.github.com/repos/ndmitchell/hlint/issues/215/labels{/name}","comments_url":"https://api.github.com/repos/ndmitchell/hlint/issues/215/comments","events_url":"https://api.github.com/repos/ndmitchell/hlint/issues/215/events","html_url":"https://github.com/ndmitchell/hlint/issues/215","id":131023171,"number":215,"title":"HLint ignores deriving inside family instances","user":{"login":"mishun","id":1227703,"avatar_url":"https://avatars.githubusercontent.com/u/1227703?v=3","gravatar_id":"","url":"https://api.github.com/users/mishun","html_url":"https://github.com/mishun","followers_url":"https://api.github.com/users/mishun/followers","following_url":"https://api.github.com/users/mishun/following{/other_user}","gists_url":"https://api.github.com/users/mishun/gists{/gist_id}","starred_url":"https://api.github.com/users/mishun/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mishun/subscriptions","organizations_url":"https://api.github.com/users/mishun/orgs","repos_url":"https://api.github.com/users/mishun/repos","events_url":"https://api.github.com/users/mishun/events{/privacy}","received_events_url":"https://api.github.com/users/mishun/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2016-02-03T13:21:40Z","updated_at":"2016-02-03T21:32:54Z","closed_at":null,"body":"Working example:\r\n```Haskell\r\n{-# LANGUAGE GeneralizedNewtypeDeriving, TypeFamilies #-}\r\nmodule Main where\r\n\r\nimport Control.Applicative\r\n\r\nclass Class x where\r\n    data MyIO x :: * -> *\r\n\r\ninstance Class Int where\r\n    newtype MyIO Int a = MyIO { unIO :: IO a }\r\n        deriving (Functor, Applicative, Monad)\r\n\r\nhello :: MyIO Int ()\r\nhello = do\r\n    MyIO $ putStrLn \"Hello\"\r\n    MyIO $ putStrLn \"World\"\r\n\r\nmain :: IO ()\r\nmain = unIO hello\r\n```\r\nhlint-1.9.27 outputs:\r\n```\r\nWarning: Unused LANGUAGE pragma\r\nFound:\r\n  {-# LANGUAGE GeneralizedNewtypeDeriving, TypeFamilies #-}\r\nWhy not:\r\n  {-# LANGUAGE TypeFamilies #-}\r\n\r\n1 hint\r\n```"},"comment":{"url":"https://api.github.com/repos/ndmitchell/hlint/issues/comments/179481430","html_url":"https://github.com/ndmitchell/hlint/issues/215#issuecomment-179481430","issue_url":"https://api.github.com/repos/ndmitchell/hlint/issues/215","id":179481430,"user":{"login":"ndmitchell","id":1651197,"avatar_url":"https://avatars.githubusercontent.com/u/1651197?v=3","gravatar_id":"","url":"https://api.github.com/users/ndmitchell","html_url":"https://github.com/ndmitchell","followers_url":"https://api.github.com/users/ndmitchell/followers","following_url":"https://api.github.com/users/ndmitchell/following{/other_user}","gists_url":"https://api.github.com/users/ndmitchell/gists{/gist_id}","starred_url":"https://api.github.com/users/ndmitchell/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ndmitchell/subscriptions","organizations_url":"https://api.github.com/users/ndmitchell/orgs","repos_url":"https://api.github.com/users/ndmitchell/repos","events_url":"https://api.github.com/users/ndmitchell/events{/privacy}","received_events_url":"https://api.github.com/users/ndmitchell/received_events","type":"User","site_admin":false},"created_at":"2016-02-03T21:32:54Z","updated_at":"2016-02-03T21:32:54Z","body":"Thanks for the test case, all fixed now. I'll make a new release tomorrow."}}