{"action":"created","issue":{"url":"https://api.github.com/repos/ekmett/indexed/issues/2","labels_url":"https://api.github.com/repos/ekmett/indexed/issues/2/labels{/name}","comments_url":"https://api.github.com/repos/ekmett/indexed/issues/2/comments","events_url":"https://api.github.com/repos/ekmett/indexed/issues/2/events","html_url":"https://github.com/ekmett/indexed/issues/2","id":90425060,"number":2,"title":"GHC HEAD trouble","user":{"login":"ggreif","id":1312006,"avatar_url":"https://avatars.githubusercontent.com/u/1312006?v=3","gravatar_id":"","url":"https://api.github.com/users/ggreif","html_url":"https://github.com/ggreif","followers_url":"https://api.github.com/users/ggreif/followers","following_url":"https://api.github.com/users/ggreif/following{/other_user}","gists_url":"https://api.github.com/users/ggreif/gists{/gist_id}","starred_url":"https://api.github.com/users/ggreif/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ggreif/subscriptions","organizations_url":"https://api.github.com/users/ggreif/orgs","repos_url":"https://api.github.com/users/ggreif/repos","events_url":"https://api.github.com/users/ggreif/events{/privacy}","received_events_url":"https://api.github.com/users/ggreif/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-06-23T15:51:06Z","updated_at":"2015-06-24T13:26:08Z","closed_at":null,"body":"I get below errors when building with HEAD GHC\r\n```\r\nsrc/Indexed/Types.hs:142:10: error:\r\n    Could not deduce (Typeable At)\r\n      arising from the superclasses of an instance declaration\r\n    from the context: (Data a, Typeable i, i ~ j)\r\n      bound by the instance declaration at src/Indexed/Types.hs:142:10-55\r\n    In the instance declaration for ?Data (At a i j)?\r\n\r\nsrc/Indexed/Types.hs:193:10: error:\r\n    Could not deduce (Typeable Coat)\r\n      arising from the superclasses of an instance declaration\r\n    from the context: (Data a, Typeable i, i ~ j)\r\n      bound by the instance declaration at src/Indexed/Types.hs:193:10-57\r\n    In the instance declaration for ?Data (Coat a i j)?\r\n```\r\n\r\nI did not analyse why this happens."},"comment":{"url":"https://api.github.com/repos/ekmett/indexed/issues/comments/114866823","html_url":"https://github.com/ekmett/indexed/issues/2#issuecomment-114866823","issue_url":"https://api.github.com/repos/ekmett/indexed/issues/2","id":114866823,"user":{"login":"ggreif","id":1312006,"avatar_url":"https://avatars.githubusercontent.com/u/1312006?v=3","gravatar_id":"","url":"https://api.github.com/users/ggreif","html_url":"https://github.com/ggreif","followers_url":"https://api.github.com/users/ggreif/followers","following_url":"https://api.github.com/users/ggreif/following{/other_user}","gists_url":"https://api.github.com/users/ggreif/gists{/gist_id}","starred_url":"https://api.github.com/users/ggreif/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ggreif/subscriptions","organizations_url":"https://api.github.com/users/ggreif/orgs","repos_url":"https://api.github.com/users/ggreif/repos","events_url":"https://api.github.com/users/ggreif/events{/privacy}","received_events_url":"https://api.github.com/users/ggreif/received_events","type":"User","site_admin":false},"created_at":"2015-06-24T13:26:08Z","updated_at":"2015-06-24T13:26:08Z","body":"All the changes I have together so far:\r\n``` diff\r\ndiff --git a/src/Indexed/Types.hs b/src/Indexed/Types.hs\r\nindex 7af5513..bc7fb36 100644\r\n--- a/src/Indexed/Types.hs\r\n+++ b/src/Indexed/Types.hs\r\n@@ -6,7 +6,7 @@\r\n {-# LANGUAGE RankNTypes #-}\r\n {-# LANGUAGE Trustworthy #-}\r\n {-# LANGUAGE ScopedTypeVariables #-}\r\n-{-# LANGUAGE DeriveDataTypeable #-}\r\n+{-# LANGUAGE DeriveDataTypeable, FlexibleContexts, UndecidableInstances #-}\r\n -----------------------------------------------------------------------------\r\n -- |\r\n -- Module      :  Indexed.Types\r\n@@ -21,7 +21,7 @@\r\n module Indexed.Types\r\n   (\r\n   -- * Natural Transformations\r\n-    (~>)()\r\n+    type (~>)\r\n   , (:~>)(Nat,($$))\r\n   -- * Limits\r\n   , Lim\r\n@@ -139,7 +139,7 @@ instance (Monoid m, i ~ j) => Monoid (At m i j) where\r\n -- | Type alias for indexed monads, functors, etc. in Bob Atkey's style.\r\n type Atkey f i j a = f (At a j) i\r\n \r\n-instance (Data a, Typeable i, i ~ j) => Data (At a i j) where\r\n+instance (Data a, Typeable (At a i j), i ~ j) => Data (At a i j) where\r\n   gfoldl f z (At a) = z At `f` a\r\n   toConstr _ = atConstr\r\n   gunfold k z c = case constrIndex c of\r\n@@ -190,7 +190,7 @@ uncoat (Coat a) = a\r\n -- | Type alias for indexed monads, functors, etc. in Bob Atkey's style.\r\n type Coatkey f i j a = f (Coat a j) i\r\n \r\n-instance (Data a, Typeable i, i ~ j) => Data (Coat a i j) where\r\n+instance (Data a, Typeable (Coat a i j), i ~ j) => Data (Coat a i j) where\r\n   gfoldl f z (Coat a) = z (\\x -> Coat x) `f` a\r\n   toConstr _ = coatConstr\r\n   gunfold k z c = case constrIndex c of\r\n```"}}