Fix build with mtl^>=2.3

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Revision history for quickcheck-lockstep
 
+## 0.4.1 -- 2024-02-21
+
+* PATCH: fix compilation failures when using `mtl ^>=2.3`
+
 ## 0.4.0 -- 2024-02-17
 
 * BREAKING: Counter-examples now produce valid code. To facilitate this,

src/Test/QuickCheck/StateModel/Lockstep/Op/SumProd.hs

@@ -1,12 +1,8 @@
-{-# LANGUAGE CPP #-}
-
 module Test.QuickCheck.StateModel.Lockstep.Op.SumProd (Op(..), intOpId) where
 
-#if __GLASGOW_HASKELL__ >= 906
 import Control.Monad ((<=<))
-#endif
 import Control.Monad.Reader (ReaderT)
-import Control.Monad.State
+import Control.Monad.State (StateT)
 import GHC.Show (appPrec)
 
 import Test.QuickCheck.StateModel.Lockstep.Op

src/Test/QuickCheck/StateModel/Lockstep/Run.hs

@@ -1,5 +1,3 @@
-{-# LANGUAGE CPP #-}
-
 -- | Run lockstep tests
 --
 -- Intended for qualified import.
@@ -17,11 +15,7 @@ module Test.QuickCheck.StateModel.Lockstep.Run (
 import Prelude hiding (init)
 
 import Control.Exception
-#if __GLASGOW_HASKELL__ >= 906
 import Control.Monad (void)
-#else
-import Control.Monad.Reader
-#endif
 import Data.Set (Set)
 import Data.Set qualified as Set
 import Data.Typeable

test/Test/MockFS.hs

@@ -16,8 +16,8 @@ module Test.MockFS (tests) where
 import Prelude hiding (init)
 
 import Control.Exception (catch, throwIO)
-import Control.Monad
-import Control.Monad.Reader
+import Control.Monad (replicateM, (<=<))
+import Control.Monad.Reader (ReaderT (..))
 import Data.Bifunctor
 import Data.Set (Set)
 import Data.Set qualified as Set