Fix compilation with GHC-7.8.4

jaspervdj · Jan 24, 2019 · 82dc886 · 82dc886
1 parent b3e3257
commit 82dc886
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/Patat/Images/Internal.hs b/src/Patat/Images/Internal.hs
@@ -1,4 +1,5 @@
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+{-# LANGUAGE DeriveDataTypeable        #-}
 {-# LANGUAGE ExistentialQuantification #-}
 module Patat.Images.Internal
     ( Config (..)
@@ -11,6 +12,8 @@ module Patat.Images.Internal
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 import           Control.Exception (Exception)
 import qualified Data.Aeson        as A
+import           Data.Data         (Data)
+import           Data.Typeable     (Typeable)
 
 
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@@ -23,7 +26,7 @@ data Backend = forall a. A.FromJSON a => Backend (Config a -> IO Handle)
 
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 data BackendNotSupported = BackendNotSupported String
-    deriving (Show)
+    deriving (Data, Show, Typeable)
 
 
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