Fix shake-bench to build with aeson 2.x

Author: pepeiborra

shake-bench/src/Development/Benchmark/Rules.hs

@@ -504,8 +504,10 @@ instance FromJSON GitCommit where
   parseJSON o@(Object _) = do
     let keymap = o ^. _Object
     case toList keymap of
-      [(name, String gitName)] -> pure $ GitCommit gitName (Just name) Nothing True
-      [(name, Object props)] ->
+      -- excuse me for the hack to maintain compatibility with aeson 2.0
+      [(T.pack . show -> name, String gitName)] ->
+        pure $ GitCommit gitName (Just name) Nothing True
+      [(T.pack . show -> name, Object props)] ->
         GitCommit
           <$> props .:? "git"  .!= name
           <*> pure (Just name)