Fixed compilation with GHC 9.2

effectful-th/src/Effectful/TH.hs

@@ -75,7 +75,8 @@ makeSendFunctionFor tinfo cinfo = do
   let replaceEff = map (pure . replaceTV m effMonad)
 
   -- Create the function's type signature.
-  let bndrs = effectVarBndrs <> constructorVars cinfo <> [esBndr, rBndr]
+  let bndrs = map (mapTVFlag (const inferredSpec)) $
+        effectVarBndrs <> constructorVars cinfo <> [esBndr, rBndr]
 
   let effect = appsT $ conT (datatypeName tinfo) : map varT effectVars
       effectConstraint = [t| $(effect) :> $(varT es) |]
@@ -86,7 +87,7 @@ makeSendFunctionFor tinfo cinfo = do
       eff = [t| Eff $(varT es) $(varT r) |]
       funSig = arrowsT args eff
 
-  sig <- sigD fname $ forallT bndrs ctx funSig
+  sig <- withDoc $ sigD fname $ forallT bndrs ctx funSig
 
   -- Create the function's definition.
   ns <- let
@@ -101,14 +102,16 @@ makeSendFunctionFor tinfo cinfo = do
 
   defn <- funD fname [clause pats body []]
 
+  pure [sig, defn]
+  where
+    withDoc :: Q Dec -> Q Dec
 #if MIN_VERSION_template_haskell(2,18,0)
-  let doc :: String
-      doc = "-- | Send the '"
-        <> show (constructorName cinfo)
-        <> "' effect to the effect handler."
-  pure [withDecDoc doc sig, defn]
+    withDoc = withDecDoc
+      $  "-- | Send the '"
+      <> show (constructorName cinfo)
+      <> "' effect to the effect handler."
 #else
-  pure [sig, defn]
+    withDoc = id
 #endif
 
 toFunctionName :: Name -> Name

effectful-th/tests/Fail.hs

@@ -1,6 +1,8 @@
 {-# LANGUAGE TemplateHaskell #-}
 module Fail where
 
+import Prelude hiding (fail)
+
 import Effectful.Fail (Fail)
 import Effectful.TH