load Control.Monad.Fail if GHC < 8.8

Author: Anton-Latukha

src/Nix/Fresh/Stable.hs

@@ -14,7 +14,10 @@ import Nix.Effects
 import Nix.Render
 import Nix.Thunk
 import Nix.Thunk.StableId
+#if __GLASGOW_HASKELL__ < 880
+import Prelude hiding (fail)
 import Control.Monad.Fail
+#endif
 import Control.Monad.Reader
 import Control.Monad.State.Strict
 import Control.Monad.Ref

src/Nix/Scope/Basic.hs

@@ -19,7 +19,10 @@ module Nix.Scope.Basic where
 
 import Control.Applicative
 import Control.Monad.Exception
+#if __GLASGOW_HASKELL__ < 880
+import Prelude hiding (fail)
 import Control.Monad.Fail
+#endif
 import Control.Monad.Reader
 import Control.Monad.State
 import Control.Monad.Catch

src/Nix/Thunk/Basic.hs

@@ -18,7 +18,10 @@ module Nix.Thunk.Basic (ThunkT (..), runThunkT, NThunkF (..), Deferred (..)) whe
 
 import           Control.Exception       hiding ( catch )
 import           Control.Monad.Catch
+#if __GLASGOW_HASKELL__ < 880
+import           Prelude hiding (fail)
 import           Control.Monad.Fail
+#endif
 import           Control.Monad.Reader
 import           Control.Monad.State