diff --git a/compiler/GHC/Core/Ppr.hs b/compiler/GHC/Core/Ppr.hs
--- a/compiler/GHC/Core/Ppr.hs
+++ b/compiler/GHC/Core/Ppr.hs
@@ -22,7 +22,7 @@
         pprCoreExpr, pprParendExpr,
         pprCoreBinding, pprCoreBindings, pprCoreAlt,
         pprCoreBindingWithSize, pprCoreBindingsWithSize,
-        pprCoreBinder, pprCoreBinders,
+        pprCoreBinder, pprCoreBinders, pprId, pprIds,
         pprRule, pprRules, pprOptCo,
         pprOcc, pprOccWithTick
     ) where
@@ -465,6 +465,13 @@
 -- Print a type variable binder with its kind (but not if *)
 pprKindedTyVarBndr tyvar
   = text "@" <> pprTyVar tyvar
+
+-- pprId x prints x :: ty
+pprId :: Id -> SDoc
+pprId x = ppr x <+> dcolon <+> ppr (idType x)
+
+pprIds :: [Id] -> SDoc
+pprIds xs = sep (map pprId xs)
 
 -- pprIdBndr does *not* print the type
 -- When printing any Id binder in debug mode, we print its inline pragma and one-shot-ness
diff --git a/compiler/GHC/Core/Rules.hs b/compiler/GHC/Core/Rules.hs
--- a/compiler/GHC/Core/Rules.hs
+++ b/compiler/GHC/Core/Rules.hs
@@ -405,7 +405,7 @@
 -- See Note [Extra args in the target]
 -- See comments on matchRule
 lookupRule opts rule_env@(in_scope,_) is_active fn args rules
-  = -- pprTrace "matchRules" (ppr fn <+> ppr args $$ ppr rules ) $
+  = -- pprTrace "lookupRule" (ppr fn <+> ppr args $$ ppr rules $$ ppr in_scope) $
     case go [] rules of
         []     -> Nothing
         (m:ms) -> Just (findBest in_scope (fn,args') m ms)
diff --git a/compiler/GHC/Core/Subst.hs b/compiler/GHC/Core/Subst.hs
--- a/compiler/GHC/Core/Subst.hs
+++ b/compiler/GHC/Core/Subst.hs
@@ -24,7 +24,7 @@
         emptySubst, mkEmptySubst, mkSubst, mkOpenSubst, substInScope, isEmptySubst,
         extendIdSubst, extendIdSubstList, extendTCvSubst, extendTvSubstList,
         extendSubst, extendSubstList, extendSubstWithVar, zapSubstEnv,
-        extendInScope, extendInScopeList, extendInScopeIds,
+        extendSubstInScope, extendSubstInScopeList, extendSubstInScopeSet,
         isInScope, setInScope, getTCvSubst, extendTvSubst, extendCvSubst,
         delBndr, delBndrs,
 
@@ -50,7 +50,7 @@
 import GHC.Core.Coercion hiding ( substCo, substCoVarBndr )
 
 import GHC.Types.Var.Set
-import GHC.Types.Var.Env
+import GHC.Types.Var.Env as InScopeSet
 import GHC.Types.Id
 import GHC.Types.Name     ( Name )
 import GHC.Types.Var
@@ -284,25 +284,23 @@
 isInScope :: Var -> Subst -> Bool
 isInScope v (Subst in_scope _ _ _) = v `elemInScopeSet` in_scope
 
--- | Add the 'Var' to the in-scope set: as a side effect,
--- and remove any existing substitutions for it
-extendInScope :: Subst -> Var -> Subst
-extendInScope (Subst in_scope ids tvs cvs) v
-  = Subst (in_scope `extendInScopeSet` v)
-          (ids `delVarEnv` v) (tvs `delVarEnv` v) (cvs `delVarEnv` v)
+-- | Add the 'Var' to the in-scope set
+extendSubstInScope :: Subst -> Var -> Subst
+extendSubstInScope (Subst in_scope ids tvs cvs) v
+  = Subst (in_scope `InScopeSet.extendInScopeSet` v)
+          ids tvs cvs
 
 -- | Add the 'Var's to the in-scope set: see also 'extendInScope'
-extendInScopeList :: Subst -> [Var] -> Subst
-extendInScopeList (Subst in_scope ids tvs cvs) vs
+extendSubstInScopeList :: Subst -> [Var] -> Subst
+extendSubstInScopeList (Subst in_scope ids tvs cvs) vs
   = Subst (in_scope `extendInScopeSetList` vs)
-          (ids `delVarEnvList` vs) (tvs `delVarEnvList` vs) (cvs `delVarEnvList` vs)
+          ids tvs cvs
 
--- | Optimized version of 'extendInScopeList' that can be used if you are certain
--- all the things being added are 'Id's and hence none are 'TyVar's or 'CoVar's
-extendInScopeIds :: Subst -> [Id] -> Subst
-extendInScopeIds (Subst in_scope ids tvs cvs) vs
-  = Subst (in_scope `extendInScopeSetList` vs)
-          (ids `delVarEnvList` vs) tvs cvs
+-- | Add the 'Var's to the in-scope set: see also 'extendInScope'
+extendSubstInScopeSet :: Subst -> VarSet -> Subst
+extendSubstInScopeSet (Subst in_scope ids tvs cvs) vs
+  = Subst (in_scope `extendInScopeSetSet` vs)
+          ids tvs cvs
 
 setInScope :: Subst -> InScopeSet -> Subst
 setInScope (Subst _ ids tvs cvs) in_scope = Subst in_scope ids tvs cvs
@@ -462,7 +460,7 @@
 
 substIdBndr _doc rec_subst subst@(Subst in_scope env tvs cvs) old_id
   = -- pprTrace "substIdBndr" (doc $$ ppr old_id $$ ppr in_scope) $
-    (Subst (in_scope `extendInScopeSet` new_id) new_env tvs cvs, new_id)
+    (Subst (in_scope `InScopeSet.extendInScopeSet` new_id) new_env tvs cvs, new_id)
   where
     id1 = uniqAway in_scope old_id      -- id1 is cloned if necessary
     id2 | no_type_change = id1
@@ -532,7 +530,7 @@
             -> (Subst, Id)              -- Transformed pair
 
 clone_id rec_subst subst@(Subst in_scope idvs tvs cvs) (old_id, uniq)
-  = (Subst (in_scope `extendInScopeSet` new_id) new_idvs tvs new_cvs, new_id)
+  = (Subst (in_scope `InScopeSet.extendInScopeSet` new_id) new_idvs tvs new_cvs, new_id)
   where
     id1     = setVarUnique old_id uniq
     id2     = substIdType subst id1
diff --git a/ghc-lib-parser.cabal b/ghc-lib-parser.cabal
--- a/ghc-lib-parser.cabal
+++ b/ghc-lib-parser.cabal
@@ -1,7 +1,7 @@
 cabal-version: 2.0
 build-type: Simple
 name: ghc-lib-parser
-version: 9.4.6.20230808
+version: 9.4.7.20230826
 license: BSD3
 license-file: LICENSE
 category: Development
@@ -81,16 +81,16 @@
     build-depends:
         base >= 4.15 && < 4.18,
         ghc-prim > 0.2 && < 0.10,
+        containers >= 0.5 && < 0.7,
         bytestring >= 0.10 && < 0.12,
         time >= 1.4 && < 1.13,
         exceptions == 0.10.*,
         parsec,
-        containers >= 0.5 && < 0.7,
         binary == 0.8.*,
         filepath >= 1 && < 1.5,
         directory >= 1 && < 1.4,
         array >= 0.1 && < 0.6,
-        deepseq >= 1.4 && < 1.5,
+        deepseq >= 1.4 && < 1.6,
         pretty == 1.1.*,
         transformers >= 0.5 && < 0.7,
         process >= 1 && < 1.7
diff --git a/ghc-lib/stage0/compiler/build/GHC/Settings/Config.hs b/ghc-lib/stage0/compiler/build/GHC/Settings/Config.hs
--- a/ghc-lib/stage0/compiler/build/GHC/Settings/Config.hs
+++ b/ghc-lib/stage0/compiler/build/GHC/Settings/Config.hs
@@ -21,7 +21,7 @@
 cProjectName          = "The Glorious Glasgow Haskell Compilation System"
 
 cBooterVersion        :: String
-cBooterVersion        = "9.2.7"
+cBooterVersion        = "9.2.8"
 
 cStage                :: String
 cStage                = show (1 :: Int)
diff --git a/ghc-lib/stage0/libraries/ghc-boot/build/GHC/Version.hs b/ghc-lib/stage0/libraries/ghc-boot/build/GHC/Version.hs
--- a/ghc-lib/stage0/libraries/ghc-boot/build/GHC/Version.hs
+++ b/ghc-lib/stage0/libraries/ghc-boot/build/GHC/Version.hs
@@ -3,19 +3,19 @@
 import Prelude -- See Note [Why do we import Prelude here?]
 
 cProjectGitCommitId   :: String
-cProjectGitCommitId   = "5f9929478e304868cbb6e1ea04da3f27ea4a1e8e"
+cProjectGitCommitId   = "00920f176b0235d5bb52a8e054d89a664f8938fe"
 
 cProjectVersion       :: String
-cProjectVersion       = "9.4.6"
+cProjectVersion       = "9.4.7"
 
 cProjectVersionInt    :: String
 cProjectVersionInt    = "904"
 
 cProjectPatchLevel    :: String
-cProjectPatchLevel    = "6"
+cProjectPatchLevel    = "7"
 
 cProjectPatchLevel1   :: String
-cProjectPatchLevel1   = "6"
+cProjectPatchLevel1   = "7"
 
 cProjectPatchLevel2   :: String
 cProjectPatchLevel2   = "0"
diff --git a/libraries/ghci/GHCi/Message.hs b/libraries/ghci/GHCi/Message.hs
--- a/libraries/ghci/GHCi/Message.hs
+++ b/libraries/ghci/GHCi/Message.hs
@@ -465,7 +465,7 @@
 #define MIN_VERSION_ghc_heap(major1,major2,minor) (\
   (major1) <  9 || \
   (major1) == 9 && (major2) <  4 || \
-  (major1) == 9 && (major2) == 4 && (minor) <= 6)
+  (major1) == 9 && (major2) == 4 && (minor) <= 7)
 #endif /* MIN_VERSION_ghc_heap */
 #if MIN_VERSION_ghc_heap(8,11,0)
 instance Binary Heap.StgTSOProfInfo