From 9a624f197fb187f066b5807f00b908a3e86eba31 Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Sun, 3 May 2026 10:24:08 +0530
Subject: [PATCH 01/10] Fix code for the internal-dev flag to work

---
 src/Streamly/Internal/Data/SmallArray.hs    |  2 +-
 src/Streamly/Internal/FileSystem/FD.hs      | 18 +++++------
 src/Streamly/Internal/System/IOVec.hs       | 35 ++++++++-------------
 src/Streamly/Internal/System/IOVec/Type.hsc | 14 +++++++++
 4 files changed, 36 insertions(+), 33 deletions(-)

diff --git a/src/Streamly/Internal/Data/SmallArray.hs b/src/Streamly/Internal/Data/SmallArray.hs
index c351860594..ddb5d11fe6 100644
--- a/src/Streamly/Internal/Data/SmallArray.hs
+++ b/src/Streamly/Internal/Data/SmallArray.hs
@@ -41,7 +41,7 @@ module Streamly.Internal.Data.SmallArray
   )
 where
 
-import Prelude hiding (foldr, length, read)
+import Prelude hiding (foldl', foldr, length, read)
 import Control.DeepSeq (NFData(..))
 import Control.Monad (when)
 import Control.Monad.IO.Class (MonadIO, liftIO)
diff --git a/src/Streamly/Internal/FileSystem/FD.hs b/src/Streamly/Internal/FileSystem/FD.hs
index 1da8c004dc..21970a0844 100644
--- a/src/Streamly/Internal/FileSystem/FD.hs
+++ b/src/Streamly/Internal/FileSystem/FD.hs
@@ -125,21 +125,19 @@ import System.IO (IOMode)
 import Prelude hiding (read)
 
 import qualified GHC.IO.FD as FD
-import qualified GHC.IO.Device as RawIO
+import qualified GHC.IO.Device as GHCDevice
 
 import Streamly.Data.Array (Array, Unbox)
 import Streamly.Data.Stream (Stream)
 
-import Streamly.Internal.Data.Array (byteLength, unsafeFreeze, unsafePinnedAsPtr)
+import Streamly.Internal.Data.Array (unsafeFreeze, unsafePinnedAsPtr)
 import Streamly.Internal.System.IO (defaultChunkSize)
 
 #if !defined(mingw32_HOST_OS)
-{-
 import Streamly.Internal.Data.Stream.IsStream.Type (toStreamD)
 import Streamly.Internal.System.IOVec (groupIOVecsOf)
-import qualified Streamly.Internal.FileSystem.FDIO as RawIO hiding (write)
+import qualified Streamly.Internal.FileSystem.FDIO as RawIO
 import qualified Streamly.Internal.System.IOVec.Type as RawIO
--}
 #endif
 -- import Streamly.Data.Fold (Fold)
 -- import Streamly.String (encodeUtf8, decodeUtf8, foldLines)
@@ -147,7 +145,7 @@ import qualified Streamly.Internal.System.IOVec.Type as RawIO
 import qualified Streamly.Data.Array as A
 import qualified Streamly.Data.Fold as FL
 import qualified Streamly.Internal.Data.MutArray as MArray
-    (MutArray(..), unsafePinnedAsPtr, pinnedNewBytes)
+    (MutArray(..), unsafePinnedAsPtr, pinnedNewBytes, unsafeCreateWithPtr')
 import qualified Streamly.Internal.Data.Array.Stream as AS
 import qualified Streamly.Internal.Data.Stream as S
 import qualified Streamly.Internal.Data.Stream as D
@@ -222,7 +220,7 @@ readArrayUpto size (Handle fd) = do
         MArray.unsafeCreateWithPtr' size $ \p ->
              -- n <- hGetBufSome h p size
 #if MIN_VERSION_base(4,15,0)
-            RawIO.read fd p 0 size
+            GHCDevice.read fd p 0 size
 #else
             RawIO.read fd p size
 #endif
@@ -241,10 +239,10 @@ readArrayUpto size (Handle fd) = do
 writeArray :: Unbox a => Handle -> Array a -> IO ()
 writeArray _ arr | A.length arr == 0 = return ()
 writeArray (Handle fd) arr =
-    unsafePinnedAsPtr arr $ \p ->
+    unsafePinnedAsPtr arr $ \p aLen ->
     -- RawIO.writeAll fd (castPtr p) aLen
 #if MIN_VERSION_base(4,15,0)
-    RawIO.write fd (castPtr p) 0 aLen
+    GHCDevice.write fd (castPtr p) 0 aLen
 #else
     RawIO.write fd (castPtr p) aLen
 #endif
@@ -254,9 +252,9 @@ writeArray (Handle fd) arr =
     let iov' = iov {arrEnd = arrBound iov}
     A.writeIndex iov' 0 (RawIO.IOVec (castPtr p) (fromIntegral aLen))
     RawIO.writevAll fd (unsafeForeignPtrToPtr (aStart iov')) 1
-    -}
     where
     aLen = byteLength arr
+    -}
 
 #if !defined(mingw32_HOST_OS)
 {-
diff --git a/src/Streamly/Internal/System/IOVec.hs b/src/Streamly/Internal/System/IOVec.hs
index e0a7e1cd55..4d94881a99 100644
--- a/src/Streamly/Internal/System/IOVec.hs
+++ b/src/Streamly/Internal/System/IOVec.hs
@@ -15,10 +15,8 @@ module Streamly.Internal.System.IOVec
     , c_writev
     , c_safe_writev
 #if !defined(mingw32_HOST_OS)
-{-
     , groupIOVecsOf
     , groupIOVecsOfMut
--}
 #endif
     )
 where
@@ -26,18 +24,15 @@ where
 #include "inline.hs"
 
 #if !defined(mingw32_HOST_OS)
-{-
 import Control.Monad (when)
 import Control.Monad.IO.Class (MonadIO(..))
 import Foreign.Ptr (castPtr)
-import Streamly.Internal.Data.MutArray (length)
+import Streamly.Internal.Data.MutArray (length, MutArray(..))
 import Streamly.Internal.Data.SVar.Type (adaptState)
-import Streamly.Internal.Data.MutArray (Array(..))
 
 import qualified Streamly.Internal.Data.Array as Array
-import qualified Streamly.Internal.Data.MutArray.Type as MArray
+import qualified Streamly.Internal.Data.MutArray as MArray
 import qualified Streamly.Internal.Data.Stream as D
--}
 #endif
 
 import Streamly.Internal.System.IOVec.Type
@@ -45,7 +40,6 @@ import Streamly.Internal.System.IOVec.Type
 import Prelude hiding (length)
 
 #if !defined(mingw32_HOST_OS)
-{-
 data GatherState s arr
     = GatherInitial s
     | GatherBuffering s arr Int
@@ -59,7 +53,7 @@ data GatherState s arr
 -- @since 0.7.0
 {-# INLINE_NORMAL groupIOVecsOfMut #-}
 groupIOVecsOfMut :: MonadIO m
-    => Int -> Int -> D.Stream m (Array a) -> D.Stream m (Array IOVec)
+    => Int -> Int -> D.Stream m (MutArray a) -> D.Stream m (MutArray IOVec)
 groupIOVecsOfMut n maxIOVLen (D.Stream step state) =
     D.Stream step' (GatherInitial state)
 
@@ -78,11 +72,10 @@ groupIOVecsOfMut n maxIOVLen (D.Stream step state) =
         r <- step (adaptState gst) st
         case r of
             D.Yield arr s -> do
-                let p = arrStart arr
-                    len = MArray.byteLength arr
-                iov <- liftIO $ MArray.newArray maxIOVLen
-                iov' <- liftIO $ MArray.snocUnsafe iov (IOVec (castPtr p)
-                                                (fromIntegral len))
+                let len = MArray.byteLength arr
+                iov <- liftIO $ MArray.new maxIOVLen
+                iov' <- MArray.unsafeAsPtr arr $ \p _ ->
+                    MArray.snocUnsafe iov (IOVec (castPtr p) (fromIntegral len))
                 if len >= n
                 then return $ D.Skip (GatherYielding iov' (GatherInitial s))
                 else return $ D.Skip (GatherBuffering s iov' len)
@@ -93,19 +86,18 @@ groupIOVecsOfMut n maxIOVLen (D.Stream step state) =
         r <- step (adaptState gst) st
         case r of
             D.Yield arr s -> do
-                let p = arrStart arr
-                    alen = MArray.byteLength arr
+                let alen = MArray.byteLength arr
                     len' = len + alen
                 if len' > n || length iov >= maxIOVLen
                 then do
-                    iov' <- liftIO $ MArray.newArray maxIOVLen
-                    iov'' <- liftIO $ MArray.snocUnsafe iov' (IOVec (castPtr p)
-                                                      (fromIntegral alen))
+                    iov' <- liftIO $ MArray.new maxIOVLen
+                    iov'' <- MArray.unsafeAsPtr arr $ \p _ ->
+                        MArray.snocUnsafe iov' (IOVec (castPtr p) (fromIntegral alen))
                     return $ D.Skip (GatherYielding iov
                                         (GatherBuffering s iov'' alen))
                 else do
-                    iov' <- liftIO $ MArray.snocUnsafe iov (IOVec (castPtr p)
-                                                    (fromIntegral alen))
+                    iov' <- MArray.unsafeAsPtr arr $ \p _ ->
+                        MArray.snocUnsafe iov (IOVec (castPtr p) (fromIntegral alen))
                     return $ D.Skip (GatherBuffering s iov' len')
             D.Skip s -> return $ D.Skip (GatherBuffering s iov len)
             D.Stop -> return $ D.Skip (GatherYielding iov GatherFinish)
@@ -128,5 +120,4 @@ groupIOVecsOf n maxIOVLen str =
     D.map Array.unsafeFreeze
         $ groupIOVecsOfMut n maxIOVLen
         $ D.map Array.unsafeThaw str
--}
 #endif
diff --git a/src/Streamly/Internal/System/IOVec/Type.hsc b/src/Streamly/Internal/System/IOVec/Type.hsc
index 6955c5b553..c15e90df32 100644
--- a/src/Streamly/Internal/System/IOVec/Type.hsc
+++ b/src/Streamly/Internal/System/IOVec/Type.hsc
@@ -31,6 +31,7 @@ import Foreign.Ptr (Ptr)
 import System.Posix.Types (CSsize(..))
 #if !defined(mingw32_HOST_OS)
 import Foreign.Storable (Storable(..))
+import Streamly.Internal.Data.MutByteArray (Unbox(..))
 #endif
 
 -------------------------------------------------------------------------------
@@ -62,6 +63,19 @@ instance Storable IOVec where
           len  :: #{type size_t} = iovLen vec
       #{poke struct iovec, iov_base} ptr base
       #{poke struct iovec, iov_len}  ptr len
+
+instance Unbox IOVec where
+    {-# INLINE peekAt #-}
+    peekAt i arr = do
+        base <- peekAt i arr
+        len  <- peekAt (i + #{offset struct iovec, iov_len}) arr
+        return (IOVec base len)
+    {-# INLINE pokeAt #-}
+    pokeAt i arr (IOVec base len) = do
+        pokeAt i arr base
+        pokeAt (i + #{offset struct iovec, iov_len}) arr len
+    {-# INLINE sizeOf #-}
+    sizeOf _ = #{size struct iovec}
 #endif
 
 -- capi calling convention does not work without -fobject-code option with GHCi

From 1ef03ce2929502a3769c8317de107b13ef7488cc Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Tue, 5 May 2026 10:56:01 +0530
Subject: [PATCH 02/10] Cleanup internal-dev build flag, use a cabal.project
 file

---
 .packcheck.ignore                             |  1 +
 benchmark/streamly-benchmarks.cabal           | 13 +---
 cabal.project.dev                             | 44 +++++++++++++
 core/src/Streamly/Internal/Data/Array.hs      |  6 +-
 core/src/Streamly/Internal/Data/Array/Type.hs | 48 +++++---------
 .../Streamly/Internal/Data/MutArray/Type.hs   | 65 +++----------------
 .../Streamly/Internal/Data/Serialize/Type.hs  |  6 +-
 core/streamly-core.cabal                      |  9 +--
 streamly.cabal                                | 14 +---
 9 files changed, 78 insertions(+), 128 deletions(-)
 create mode 100644 cabal.project.dev

diff --git a/.packcheck.ignore b/.packcheck.ignore
index 66b8033047..f2b44a794b 100644
--- a/.packcheck.ignore
+++ b/.packcheck.ignore
@@ -31,6 +31,7 @@ cabal.project.markdown-doctest
 cabal.project.streamly
 cabal.project.Werror
 cabal.project.Werror-nocode
+cabal.project.dev
 core/
 examples/README.md
 flake.lock
diff --git a/benchmark/streamly-benchmarks.cabal b/benchmark/streamly-benchmarks.cabal
index 34815a1629..17738465f8 100644
--- a/benchmark/streamly-benchmarks.cabal
+++ b/benchmark/streamly-benchmarks.cabal
@@ -110,9 +110,6 @@ common compile-options
     -- if flag(use-streamly-core)
     --   cpp-options:    -DUSE_STREAMLY_CORE
 
-    if flag(dev)
-      cpp-options:    -DDEVBUILD
-
     if flag(include-strict-utf8)
       cpp-options:    -DINCLUDE_STRICT_UTF8
 
@@ -146,10 +143,6 @@ common compile-options
     if flag(has-llvm)
       ghc-options: -fllvm
 
-    if flag(dev)
-      ghc-options:    -Wmissed-specialisations
-                      -Wall-missed-specialisations
-
 common optimization-options
   if flag(opt)
     ghc-options: -O2
@@ -158,7 +151,7 @@ common optimization-options
                  -fmax-worker-args=16
 
     -- For this to be effective it must come after the -O2 option
-    if flag(dev) || flag(debug)
+    if flag(debug)
       ghc-options: -fno-ignore-asserts
 
     if flag(fusion-plugin) && !impl(ghcjs) && !impl(ghc < 8.6)
@@ -205,10 +198,6 @@ common bench-depends
     build-depends:
         template-haskell   >= 2.14 && < 2.25
       , inspection-testing >= 0.4  && < 0.7
-  -- Array uses a Storable constraint in dev build making several inspection
-  -- tests fail
-  if flag(dev) && flag(inspection)
-    build-depends: inspection-and-dev-flags-cannot-be-used-together
 
 -------------------------------------------------------------------------------
 -- Library
diff --git a/cabal.project.dev b/cabal.project.dev
new file mode 100644
index 0000000000..e5d5ebfab2
--- /dev/null
+++ b/cabal.project.dev
@@ -0,0 +1,44 @@
+packages:   streamly.cabal
+          , core/streamly-core.cabal
+          , test/streamly-tests.cabal
+          , benchmark/streamly-benchmarks.cabal
+          , bench-test-lib/bench-test-lib.cabal
+
+-- For compiling standalone programs
+-- write-ghc-environment-files: always
+
+-- For debugging heap overflow
+-- jobs: 1
+
+package streamly-core
+  flags: +internal-dev
+  ghc-options:    -DDEVBUILD -DDEBUG
+                  -Wmissed-specialisations
+                  -Wall-missed-specialisations
+                  -fno-ignore-asserts
+
+package streamly
+  flags: +internal-dev
+  ghc-options:    -DDEVBUILD -DDEBUG
+                  -Wmissed-specialisations
+                  -Wall-missed-specialisations
+                  -fno-ignore-asserts
+
+package streamly-tests
+  flags: +dev
+  ghc-options:    -DDEVBUILD -DDEBUG
+                  -Wmissed-specialisations
+                  -Wall-missed-specialisations
+                  -fno-ignore-asserts
+
+package streamly-benchmarks
+  flags: +dev
+  ghc-options:    -DDEVBUILD -DDEBUG
+                  -Wmissed-specialisations
+                  -Wall-missed-specialisations
+                  -fno-ignore-asserts
+
+source-repository-package
+  type: git
+  location: https://github.com/composewell/fusion-plugin.git
+  tag: 15c0ad50a235a35e85d03cced9ad0f3938565e5a
diff --git a/core/src/Streamly/Internal/Data/Array.hs b/core/src/Streamly/Internal/Data/Array.hs
index 74a7d6849b..44ae6d8f3b 100644
--- a/core/src/Streamly/Internal/Data/Array.hs
+++ b/core/src/Streamly/Internal/Data/Array.hs
@@ -403,11 +403,7 @@ streamTransform f arr =
 --
 -- /Pre-release/
 --
-unsafeCast, castUnsafe ::
-#ifdef DEVBUILD
-    Unbox b =>
-#endif
-    Array a -> Array b
+unsafeCast, castUnsafe :: Array a -> Array b
 unsafeCast (Array contents start end) =
     Array contents start end
 RENAME(castUnsafe,unsafeCast)
diff --git a/core/src/Streamly/Internal/Data/Array/Type.hs b/core/src/Streamly/Internal/Data/Array/Type.hs
index ff65a94d0b..99080b4348 100644
--- a/core/src/Streamly/Internal/Data/Array/Type.hs
+++ b/core/src/Streamly/Internal/Data/Array/Type.hs
@@ -18,7 +18,6 @@
 module Streamly.Internal.Data.Array.Type
     (
     -- ** Type
-    -- $arrayNotes
       Array (..)
 
     -- ** Conversion
@@ -284,16 +283,15 @@ import Streamly.Internal.System.IO (unsafeInlineIO, defaultChunkSize)
 -- Array Data Type
 -------------------------------------------------------------------------------
 
--- $arrayNotes
---
--- We can use an 'Unbox' constraint in the Array type and the constraint can
--- be automatically provided to a function that pattern matches on the Array
--- type. However, it has huge performance cost, so we do not use it.
--- Investigate a GHC improvement possiblity.
---
 data Array a =
 #ifdef DEVBUILD
-    Unbox a =>
+    -- We can use an 'Unbox' constraint in the Array type and the constraint
+    -- can be automatically provided to a function that pattern matches on the
+    -- Array type. This can make the Foldable instance possible.  However, it
+    -- has huge performance cost, so we do not use it. Investigate a GHC
+    -- improvement possiblity.
+    --
+    -- Unbox a =>
 #endif
     -- All offsets are in terms of bytes from the start of arrContents
     Array
@@ -513,12 +511,7 @@ isPinned = MA.isPinned . unsafeThaw
 -- would make a copy on every splice operation, instead use the
 -- 'fromChunksK' operation to combine n immutable arrays.
 {-# INLINE splice #-}
-splice :: (MonadIO m
-#ifdef DEVBUILD
-    , Unbox a
-#endif
-    )
-    => Array a -> Array a -> m (Array a)
+splice :: MonadIO m => Array a -> Array a -> m (Array a)
 splice arr1 arr2 =
     unsafeFreeze <$> MA.spliceCopy (unsafeThaw arr1) (unsafeThaw arr2)
 
@@ -1558,11 +1551,15 @@ instance (Unbox a, Ord a) => Ord (Array a) where
     min x y = if x <= y then x else y
 
 #ifdef DEVBUILD
--- Definitions using the Unboxed constraint from the Array type. These are to
--- make the Foldable instance possible though it is much slower (7x slower).
+-- Definitions using the Unbox constraint from the Array type. If we enable the
+-- Unbox constraint in the Array type definition we can remove the constraint
+-- from here. These are to make the Foldable instance (see below) possible
+-- though it is much slower (7x slower). Need to check if the situation has
+-- changed in newer GHCs.
 --
 {-# INLINE_NORMAL _toStreamD_ #-}
-_toStreamD_ :: forall m a. MonadIO m => Int -> Array a -> D.Stream m a
+_toStreamD_ :: forall m a. (Unbox a, MonadIO m) =>
+    Int -> Array a -> D.Stream m a
 _toStreamD_ size Array{..} = D.Stream step arrStart
 
     where
@@ -1574,13 +1571,12 @@ _toStreamD_ size Array{..} = D.Stream step arrStart
         return $ D.Yield x (p + size)
 
 {-
-XXX Why isn't Unboxed implicit? This does not compile unless I use the Unboxed
-contraint.
 {-# INLINE_NORMAL _foldr #-}
 _foldr :: forall a b. (a -> b -> b) -> b -> Array a -> b
 _foldr f z arr =
     let !n = SIZE_OF(a)
     in unsafePerformIO $ D.foldr f z $ toStreamD_ n arr
+
 -- | Note that the 'Foldable' instance is 7x slower than the direct
 -- operations.
 instance Foldable Array where
@@ -1602,19 +1598,11 @@ instance Foldable Array where
 instance Unbox a => Semigroup (Array a) where
     arr1 <> arr2 = unsafePerformIO $ splice arr1 arr2
 
-empty ::
-#ifdef DEVBUILD
-    Unbox a =>
-#endif
-    Array a
+empty :: Array a
 empty = Array Unboxed.empty 0 0
 
 {-# DEPRECATED nil "Please use empty instead." #-}
-nil ::
-#ifdef DEVBUILD
-    Unbox a =>
-#endif
-    Array a
+nil :: Array a
 nil = empty
 
 instance Unbox a => Monoid (Array a) where
diff --git a/core/src/Streamly/Internal/Data/MutArray/Type.hs b/core/src/Streamly/Internal/Data/MutArray/Type.hs
index de3bd61023..fb58bf31bc 100644
--- a/core/src/Streamly/Internal/Data/MutArray/Type.hs
+++ b/core/src/Streamly/Internal/Data/MutArray/Type.hs
@@ -631,7 +631,7 @@ bytesToElemCount _ n = n `div` SIZE_OF(a)
 --
 data MutArray a =
 #ifdef DEVBUILD
-    Unbox a =>
+    -- Unbox a =>
 #endif
     -- The array is a range into arrContents. arrContents may be a superset of
     -- the slice represented by the array. All offsets are in bytes.
@@ -828,27 +828,15 @@ emptyWithAligned alloc alignSize count = liftIO $ do
 -- will mostly import the Array module qualified this should be fine.
 
 -- | Create an empty array.
-empty ::
-#ifdef DEVBUILD
-    Unbox a =>
-#endif
-    MutArray a
+empty :: MutArray a
 empty = MutArray Unboxed.empty 0 0 0
 
 {-# DEPRECATED nil "Please use empty instead." #-}
-nil ::
-#ifdef DEVBUILD
-    Unbox a =>
-#endif
-    MutArray a
+nil :: MutArray a
 nil = empty
 
 {-# INLINE newBytesAs #-}
-newBytesAs :: MonadIO m =>
-#ifdef DEVBUILD
-    Unbox a =>
-#endif
-    PinnedState -> Int -> m (MutArray a)
+newBytesAs :: MonadIO m => PinnedState -> Int -> m (MutArray a)
 newBytesAs ps bytes = do
     contents <- liftIO $ Unboxed.newAs ps bytes
     return $ MutArray
@@ -867,11 +855,7 @@ newBytesAs ps bytes = do
 -- /Pre-release/
 {-# INLINE pinnedNewBytes #-}
 {-# DEPRECATED pinnedNewBytes "Please use emptyOf' to create a Word8 array and cast it accordingly." #-}
-pinnedNewBytes :: MonadIO m =>
-#ifdef DEVBUILD
-    Unbox a =>
-#endif
-    Int -> m (MutArray a)
+pinnedNewBytes :: MonadIO m => Int -> m (MutArray a)
 pinnedNewBytes = newBytesAs Pinned
 
 -- | Like 'emptyWithAligned' but using an allocator is a pinned memory allocator and
@@ -2184,11 +2168,7 @@ data ArrayUnsafe a = ArrayUnsafe
 toArrayUnsafe :: MutArray a -> ArrayUnsafe a
 toArrayUnsafe (MutArray contents start end _) = ArrayUnsafe contents start end
 
-fromArrayUnsafe ::
-#ifdef DEVBUILD
-    Unbox a =>
-#endif
-    ArrayUnsafe a -> MutArray a
+fromArrayUnsafe :: ArrayUnsafe a -> MutArray a
 fromArrayUnsafe (ArrayUnsafe contents start end) =
          MutArray contents start end end
 
@@ -3217,13 +3197,7 @@ fromListRev xs = fromListRevN (Prelude.length xs) xs
 -- it again. We can use SIMD read/write as well.
 
 {-# INLINE cloneAs #-}
-cloneAs ::
-    ( MonadIO m
-#ifdef DEVBUILD
-    , Unbox a
-#endif
-    )
-    => PinnedState -> MutArray a -> m (MutArray a)
+cloneAs :: MonadIO m => PinnedState -> MutArray a -> m (MutArray a)
 cloneAs ps src =
     do
         let startSrc = arrStart src
@@ -3240,24 +3214,12 @@ cloneAs ps src =
 -- The new "MutArray" is unpinned in nature. Use "clone'" to clone the
 -- MutArray in pinned memory.
 {-# INLINE clone #-}
-clone ::
-    ( MonadIO m
-#ifdef DEVBUILD
-    , Unbox a
-#endif
-    )
-    => MutArray a -> m (MutArray a)
+clone :: MonadIO m => MutArray a -> m (MutArray a)
 clone = cloneAs Unpinned
 
 -- Similar to "clone" but uses pinned memory.
 {-# INLINE clone' #-}
-pinnedClone, clone' ::
-    ( MonadIO m
-#ifdef DEVBUILD
-    , Unbox a
-#endif
-    )
-    => MutArray a -> m (MutArray a)
+pinnedClone, clone' :: MonadIO m => MutArray a -> m (MutArray a)
 clone' = cloneAs Pinned
 RENAME_PRIME(pinnedClone,clone)
 
@@ -3271,9 +3233,6 @@ RENAME_PRIME(pinnedClone,clone)
 -- Note: If you freeze and splice it will create a new array.
 {-# INLINE spliceCopy #-}
 spliceCopy :: forall m a. MonadIO m =>
-#ifdef DEVBUILD
-    Unbox a =>
-#endif
     MutArray a -> MutArray a -> m (MutArray a)
 spliceCopy arr1 arr2 = do
     let start1 = arrStart arr1
@@ -3615,11 +3574,7 @@ RENAME(splitAt,breakAt)
 --
 -- /Pre-release/
 --
-castUnsafe, unsafeCast ::
-#ifdef DEVBUILD
-    Unbox b =>
-#endif
-    MutArray a -> MutArray b
+castUnsafe, unsafeCast :: MutArray a -> MutArray b
 unsafeCast (MutArray contents start end bound) =
     MutArray contents start end bound
 
diff --git a/core/src/Streamly/Internal/Data/Serialize/Type.hs b/core/src/Streamly/Internal/Data/Serialize/Type.hs
index dedf21b2e1..aa979ccc4a 100644
--- a/core/src/Streamly/Internal/Data/Serialize/Type.hs
+++ b/core/src/Streamly/Internal/Data/Serialize/Type.hs
@@ -275,11 +275,7 @@ instance forall a. Serialize a => Serialize [a] where
               pokeList (acc + 1) o1 xs
         pokeList 0 off1 val
 
-instance
-#ifdef DEVBUILD
-    Unbox a =>
-#endif
-  Serialize (Array a) where
+instance Serialize (Array a) where
     {-# INLINE addSizeTo #-}
     addSizeTo i (Array {..}) = i + (arrEnd - arrStart) + 8
 
diff --git a/core/streamly-core.cabal b/core/streamly-core.cabal
index 347bbcf344..d7498c1f98 100644
--- a/core/streamly-core.cabal
+++ b/core/streamly-core.cabal
@@ -156,9 +156,6 @@ common compile-options
     if flag(force-lstat-readdir)
       cpp-options:    -DFORCE_LSTAT_READDIR
 
-    if flag(internal-dev)
-      cpp-options:    -DDEVBUILD
-
     if flag(use-unfolds)
       cpp-options:    -DUSE_UNFOLDS_EVERYWHERE
 
@@ -196,10 +193,6 @@ common compile-options
     if flag(has-llvm)
       ghc-options: -fllvm
 
-    if flag(internal-dev)
-      ghc-options:    -Wmissed-specialisations
-                      -Wall-missed-specialisations
-
     if flag(limit-build-mem)
         ghc-options: -j1 +RTS -M500M -RTS
 
@@ -282,7 +275,7 @@ common optimization-options
                  -fmax-worker-args=16
 
   -- For this to be effective it must come after the -O2 option
-  if flag(internal-dev) || flag(debug) || !flag(opt)
+  if flag(debug) || !flag(opt)
     cpp-options: -DDEBUG
     ghc-options: -fno-ignore-asserts
 
diff --git a/streamly.cabal b/streamly.cabal
index 25c8f178f5..a7ab285174 100644
--- a/streamly.cabal
+++ b/streamly.cabal
@@ -248,9 +248,6 @@ common compile-options
     if os(windows)
       cpp-options:    -DCABAL_OS_WINDOWS
 
-    if flag(internal-dev)
-      cpp-options:    -DDEVBUILD
-
     if flag(inspection)
       cpp-options:    -DINSPECTION
 
@@ -281,10 +278,6 @@ common compile-options
     if flag(has-llvm)
       ghc-options: -fllvm
 
-    if flag(internal-dev)
-      ghc-options:    -Wmissed-specialisations
-                      -Wall-missed-specialisations
-
     if flag(limit-build-mem)
         ghc-options: +RTS -M600M -RTS
 
@@ -364,7 +357,7 @@ common optimization-options
                  -fmax-worker-args=16
 
   -- For this to be effective it must come after the -O2 option
-  if flag(internal-dev) || flag(debug) || !flag(opt)
+  if flag(debug) || !flag(opt)
     ghc-options: -fno-ignore-asserts
     cpp-options: -DDEBUG
 
@@ -589,8 +582,3 @@ library
 
     if flag(inspection)
       build-depends:   inspection-testing >= 0.4   && < 0.7
-
-    -- Array uses a Storable constraint in dev build making several inspection
-    -- tests fail
-    if flag(internal-dev) && flag(inspection)
-      build-depends: inspection-and-dev-flags-cannot-be-used-together

From f10ede5ef0dd73f1107d8b0dd055148e413dde51 Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Tue, 5 May 2026 11:35:12 +0530
Subject: [PATCH 03/10] Fix build with DEVBUILD flag, import foldr1

---
 test/lib/Streamly/Test/Prelude/Common.hs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/test/lib/Streamly/Test/Prelude/Common.hs b/test/lib/Streamly/Test/Prelude/Common.hs
index fd7474d1ff..d82f03ef2a 100644
--- a/test/lib/Streamly/Test/Prelude/Common.hs
+++ b/test/lib/Streamly/Test/Prelude/Common.hs
@@ -115,6 +115,9 @@ import Data.List
     , findIndices
     , foldl'
     , foldl1'
+#ifdef DEVBUILD
+    , foldr1
+#endif
     , insert
     , intersperse
     , isPrefixOf

From aa20233bb4f03dd8039b18ab725a4f041805a61e Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Wed, 6 May 2026 01:17:01 +0530
Subject: [PATCH 04/10] Fix SmallArray code (under internal-dev flag)

---
 src/Streamly/Data/SmallArray.hs          |  2 +-
 src/Streamly/Internal/Data/SmallArray.hs | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/Streamly/Data/SmallArray.hs b/src/Streamly/Data/SmallArray.hs
index 43c2236c71..26775c2f9e 100644
--- a/src/Streamly/Data/SmallArray.hs
+++ b/src/Streamly/Data/SmallArray.hs
@@ -14,7 +14,7 @@ module Streamly.Data.SmallArray
   , A.fromListN
   , A.fromStreamN
 
-  , A.writeN
+  , A.createOf
 
   -- * Elimination
   , A.read
diff --git a/src/Streamly/Internal/Data/SmallArray.hs b/src/Streamly/Internal/Data/SmallArray.hs
index ddb5d11fe6..8452f9bde7 100644
--- a/src/Streamly/Internal/Data/SmallArray.hs
+++ b/src/Streamly/Internal/Data/SmallArray.hs
@@ -23,7 +23,7 @@ module Streamly.Internal.Data.SmallArray
 
   , length
 
-  , writeN
+  , createOf
 
   , toStreamD
   , toStreamDRev
@@ -99,14 +99,14 @@ foldl' f z arr = runIdentity $ D.foldl' f z $ toStreamD arr
 foldr :: (a -> b -> b) -> b -> SmallArray a -> b
 foldr f z arr = runIdentity $ D.foldr f z $ toStreamD arr
 
--- | @writeN n@ folds a maximum of @n@ elements from the input stream to an
+-- | @createOf n@ folds a maximum of @n@ elements from the input stream to an
 -- 'SmallArray'.
 --
 -- Since we are folding to a 'SmallArray' @n@ should be <= 128, for larger number
 -- of elements use an 'Array' from either "Streamly.Data.Array.Generic" or "Streamly.Data.Array.Foreign".
-{-# INLINE_NORMAL writeN #-}
-writeN :: MonadIO m => Int -> Fold m a (SmallArray a)
-writeN len = FL.Fold step initial extract extract
+{-# INLINE_NORMAL createOf #-}
+createOf :: MonadIO m => Int -> Fold m a (SmallArray a)
+createOf len = FL.Fold step initial extract extract
 
     where
 

From 32ba212949b76311be9997a9094bc2023e0be15e Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Wed, 6 May 2026 01:17:34 +0530
Subject: [PATCH 05/10] Fix/hide some failing tests under the "dev" flag

---
 test/Streamly/Test/Data/Stream/Rate.hs | 6 ++++++
 test/Streamly/Test/Data/Stream/Time.hs | 2 ++
 test/Streamly/Test/Prelude/Rate.hs     | 6 ++++++
 test/Streamly/Test/Prelude/Serial.hs   | 2 ++
 test/Streamly/Test/Unicode/Char.hs     | 6 ++----
 5 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/test/Streamly/Test/Data/Stream/Rate.hs b/test/Streamly/Test/Data/Stream/Rate.hs
index aef68b7785..be97abee42 100644
--- a/test/Streamly/Test/Data/Stream/Rate.hs
+++ b/test/Streamly/Test/Data/Stream/Rate.hs
@@ -211,7 +211,9 @@ main = hspec $ do
     -- 10 0.1 second.
     let rates = [0.1, 1, 10, 100, 1000, 10000
 #ifndef __GHCJS__
+#ifdef INCLUDE_FLAKY_TESTS
                 , 100000, 1000000
+#endif
 #endif
                 ]
      in describe "async no consumer delay no producer delay" $
@@ -241,7 +243,9 @@ main = hspec $ do
 
     let rates = [0.1, 1, 10, 100, 1000, 10000
 #ifndef __GHCJS__
+#ifdef INCLUDE_FLAKY_TESTS
                 , 100000, 1000000
+#endif
 #endif
                 ]
      in describe "interleaved, no consumer delay no producer delay" $
@@ -257,7 +261,9 @@ main = hspec $ do
 
     let rates = [0.1, 1, 10, 100, 1000, 10000
 #ifndef __GHCJS__
+#ifdef INCLUDE_FLAKY_TESTS
                 , 100000, 1000000
+#endif
 #endif
                 ]
      in describe "ordered, no consumer delay no producer delay" $
diff --git a/test/Streamly/Test/Data/Stream/Time.hs b/test/Streamly/Test/Data/Stream/Time.hs
index ca4abe6ef5..41a88cffab 100644
--- a/test/Streamly/Test/Data/Stream/Time.hs
+++ b/test/Streamly/Test/Data/Stream/Time.hs
@@ -89,7 +89,9 @@ main = hspec
 #ifdef DEVBUILD
         describe "Filtering" $ do
             it "takeInterval" (testTakeInterval `shouldReturn` True)
+#ifdef INCLUDE_FLAKY_TESTS
             it "dropInterval" (testDropInterval `shouldReturn` True)
+#endif
 #endif
         it "dummy" (return () `shouldReturn` ())
 
diff --git a/test/Streamly/Test/Prelude/Rate.hs b/test/Streamly/Test/Prelude/Rate.hs
index 11c348a4dc..aee3d25e58 100644
--- a/test/Streamly/Test/Prelude/Rate.hs
+++ b/test/Streamly/Test/Prelude/Rate.hs
@@ -172,7 +172,9 @@ main = hspec $ do
     -- 10 0.1 second.
     let rates = [1, 10, 100, 1000, 10000
 #ifndef __GHCJS__
+#ifdef INCLUDE_FLAKY_TESTS
                 , 100000, 1000000
+#endif
 #endif
                 ]
      in describe "asyncly no consumer delay no producer delay" $
@@ -202,7 +204,9 @@ main = hspec $ do
 
     let rates = [1, 10, 100, 1000, 10000
 #ifndef __GHCJS__
+#ifdef INCLUDE_FLAKY_TESTS
                 , 100000, 1000000
+#endif
 #endif
                 ]
      in describe "fromWAsync, no consumer delay no producer delay" $
@@ -218,7 +222,9 @@ main = hspec $ do
 
     let rates = [1, 10, 100, 1000, 10000
 #ifndef __GHCJS__
+#ifdef INCLUDE_FLAKY_TESTS
                 , 100000, 1000000
+#endif
 #endif
                 ]
      in describe "aheadly, no consumer delay no producer delay" $
diff --git a/test/Streamly/Test/Prelude/Serial.hs b/test/Streamly/Test/Prelude/Serial.hs
index 89b731f759..945759dfb8 100644
--- a/test/Streamly/Test/Prelude/Serial.hs
+++ b/test/Streamly/Test/Prelude/Serial.hs
@@ -677,7 +677,9 @@ main = hspec
 #ifdef DEVBUILD
         describe "Filtering" $ do
             it "takeInterval" (testTakeInterval `shouldReturn` True)
+#ifdef INCLUDE_FLAKY_TESTS
             it "dropInterval" (testDropInterval `shouldReturn` True)
+#endif
 #endif
 
     -- Just some basic sanity tests for now
diff --git a/test/Streamly/Test/Unicode/Char.hs b/test/Streamly/Test/Unicode/Char.hs
index c71f68e276..69c4bdd643 100644
--- a/test/Streamly/Test/Unicode/Char.hs
+++ b/test/Streamly/Test/Unicode/Char.hs
@@ -72,11 +72,9 @@ checkNFKD :: (Text, Text, Text, Text, Text) -> IO Bool
 checkNFKD (c1, c2, c3, c4, c5) =
     checkOp "toNFKD" NFKD $ map (c5,) [c1, c2, c3, c4, c5]
 
-splitOn predicate f = S.foldMany1 (FL.takeEndBy_ predicate f)
-
 checkAllTestCases :: Int -> String -> IO ()
 checkAllTestCases lineno line = do
-    cs <- toList $ splitOn (== ';') FL.toList $ S.fromList line
+    cs <- toList $ S.splitSepBy_ (== ';') FL.toList $ S.fromList line
     case cs of
         c1 : c2 : c3 : c4 : c5 : _ -> do
             let cps = map cpToText [c1, c2, c3, c4, c5]
@@ -123,7 +121,7 @@ testNormalize file = do
         checkAll []     = return ()
 
 filesDir :: String
-filesDir = "test/Streamly/Test/Unicode"
+filesDir = "Streamly/Test/Unicode"
 
 main :: IO ()
 main = do

From 83e57ab2babadc52425d9f26eb1601072c6bec97 Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Wed, 6 May 2026 01:27:11 +0530
Subject: [PATCH 06/10] Add a CI for dev flag

---
 .github/workflows/haskell.yml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/haskell.yml b/.github/workflows/haskell.yml
index 73fa43208a..c40c28b5f6 100644
--- a/.github/workflows/haskell.yml
+++ b/.github/workflows/haskell.yml
@@ -192,13 +192,14 @@ jobs:
             subdir: core
             ignore_error: false
 
-          - name: debug-no-opt
+          # This includes the debug flag as well
+          - name: dev-no-opt
             runner: macos-latest
             command: cabal
             ghc_version: 9.14.1
             # WARNING! cannot use # comments inside pack_options.
             pack_options: >-
-              CABAL_PROJECT=cabal.project
+              CABAL_PROJECT=cabal.project.dev
               CABAL_BUILD_OPTIONS="--flag debug --flag -opt"
             ignore_error: false
 

From 5cba41a3b7a568a2145d48314d70f4170ced37d2 Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Wed, 6 May 2026 03:13:54 +0530
Subject: [PATCH 07/10] Remove nano-bench

---
 benchmark/NanoBenchmarks.hs         | 127 ----------------------------
 benchmark/streamly-benchmarks.cabal |   7 --
 streamly.cabal                      |   1 -
 3 files changed, 135 deletions(-)
 delete mode 100644 benchmark/NanoBenchmarks.hs

diff --git a/benchmark/NanoBenchmarks.hs b/benchmark/NanoBenchmarks.hs
deleted file mode 100644
index 81c142659b..0000000000
--- a/benchmark/NanoBenchmarks.hs
+++ /dev/null
@@ -1,127 +0,0 @@
-{-# OPTIONS_GHC -Wno-deprecations #-}
-
--------------------------------------------------------------------------------
--- Investigate specific benchmarks more closely in isolation, possibly looking
--- at GHC generated code for optimizing specific problematic cases.
--------------------------------------------------------------------------------
-
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-
-import Data.Char (ord)
-import Streamly.Internal.Data.Stream (Stream)
-import System.IO (hSeek, SeekMode(..), openFile, IOMode(..))
-
-import qualified Streamly.Data.Array as A
-import qualified Streamly.Internal.FileSystem.Handle as IFH
-import qualified Streamly.Data.Fold as FL
-import qualified Streamly.Internal.Data.Stream as S
-import qualified Streamly.Internal.Data.Stream.IsStream as Internal
-
-import Test.Tasty.Bench
-import System.Random
-
-maxValue :: Int
-maxValue = 100000
-
-drain :: Monad m => S.Stream m a -> m ()
-drain = S.fold FL.drain
-
-{-# INLINE sourceUnfoldrM #-}
-sourceUnfoldrM :: Monad m => Stream m Int
-sourceUnfoldrM = S.unfoldrM step 0
-    where
-    step cnt =
-        if cnt > maxValue
-        then return Nothing
-        else return (Just (cnt, cnt + 1))
-
-{-# INLINE sourceUnfoldrMN #-}
-sourceUnfoldrMN :: Monad m => Int -> Stream m Int
-sourceUnfoldrMN n = S.unfoldrM step n
-    where
-    step cnt =
-        if cnt > n
-        then return Nothing
-        else return (Just (cnt, cnt + 1))
-
-{-# INLINE sourceUnfoldr #-}
-sourceUnfoldr :: Monad m => Int -> Stream m Int
-sourceUnfoldr n = S.unfoldr step n
-    where
-    step cnt =
-        if cnt > n + maxValue
-        then Nothing
-        else Just (cnt, cnt + 1)
-
--------------------------------------------------------------------------------
--- take-drop composition
--------------------------------------------------------------------------------
-
-takeAllDropOne :: Monad m => Stream m Int -> Stream m Int
-takeAllDropOne = S.drop 1 . S.take maxValue
-
--- Requires -fspec-constr-recursive=5 for better fused code
--- The number depends on how many times we compose it
-
-{-# INLINE takeDrop #-}
-takeDrop :: Monad m => Stream m Int -> m ()
-takeDrop = drain .
-    takeAllDropOne . takeAllDropOne . takeAllDropOne . takeAllDropOne
-
--------------------------------------------------------------------------------
--- dropWhileFalse composition
--------------------------------------------------------------------------------
-
-dropWhileFalse :: Monad m => Stream m Int -> Stream m Int
-dropWhileFalse = S.dropWhile (> maxValue)
-
--- Requires -fspec-constr-recursive=5 for better fused code
--- The number depends on how many times we compose it
-
-{-# INLINE dropWhileFalseX4 #-}
-dropWhileFalseX4 :: Monad m => Stream m Int -> m ()
-dropWhileFalseX4 = drain
-    . dropWhileFalse . dropWhileFalse . dropWhileFalse .  dropWhileFalse
-
--------------------------------------------------------------------------------
--- iteration
--------------------------------------------------------------------------------
-
-{-# INLINE iterateSource #-}
-iterateSource
-    :: Monad m
-    => (Stream m Int -> Stream m Int) -> Int -> Int -> Stream m Int
-iterateSource g i n = f i (sourceUnfoldrMN n)
-    where
-        f (0 :: Int) m = g m
-        f x m = g (f (x - 1) m)
-
--- Keep only the benchmark that is to be investiagted and comment out the rest.
--- We keep all of them enabled by default for testing the build.
-main :: IO ()
-main = do
-    defaultMain [bench "unfoldr" $ nfIO $
-        randomRIO (1,1) >>= \n -> drain (sourceUnfoldr n)]
-    defaultMain [bench "take-drop" $ nfIO $ takeDrop sourceUnfoldrM]
-    defaultMain [bench "dropWhileFalseX4" $
-        nfIO $ dropWhileFalseX4 sourceUnfoldrM]
-    defaultMain [bench "iterate-mapM" $
-        nfIO $ drain $ iterateSource (S.mapM return) 100000 10]
-
-    inText <- openFile "benchmark/text-processing/gutenberg-500.txt" ReadMode
-    defaultMain [mkBenchText "splitOn abc...xyz" inText $ do
-                S.fold FL.length
-                    (Internal.splitOnSeq
-                        (A.fromList
-                            $ map (fromIntegral . ord) "abcdefghijklmnopqrstuvwxyz"
-                        )
-                        FL.drain
-                        $ IFH.read inText
-                    )
-                    >>= print
-                ]
-    where
-
-    mkBenchText name h action =
-        env (hSeek h AbsoluteSeek 0) (\_ -> bench name $ nfIO action)
diff --git a/benchmark/streamly-benchmarks.cabal b/benchmark/streamly-benchmarks.cabal
index 17738465f8..f096085952 100644
--- a/benchmark/streamly-benchmarks.cabal
+++ b/benchmark/streamly-benchmarks.cabal
@@ -649,13 +649,6 @@ benchmark Unicode.Parser
   hs-source-dirs: Streamly/Benchmark/Unicode
   main-is: Parser.hs
 
-executable nano-bench
-  import: bench-options
-  hs-source-dirs: .
-  main-is: NanoBenchmarks.hs
-  if !flag(dev)
-    buildable: False
-
 benchmark Unicode.Stream
   import: bench-options
   type: exitcode-stdio-1.0
diff --git a/streamly.cabal b/streamly.cabal
index a7ab285174..6941af9fd0 100644
--- a/streamly.cabal
+++ b/streamly.cabal
@@ -67,7 +67,6 @@ build-type:          Configure
 extra-source-files:
     bench-test-lib/bench-test-lib.cabal
     bench-test-lib/src/BenchTestLib/DirIO.hs
-    benchmark/*.hs
     benchmark/Streamly/Benchmark/Data/*.hs
     benchmark/Streamly/Benchmark/Data/Array.hs
     benchmark/Streamly/Benchmark/Data/Array/Common.hs

From 6fbbba85ba4b5679b677bd547f606337393e8c2b Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Wed, 6 May 2026 04:13:43 +0530
Subject: [PATCH 08/10] Disable the Rate tests in CI

---
 test/streamly-tests.cabal | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/streamly-tests.cabal b/test/streamly-tests.cabal
index 23b1f3e8ca..bbc8eba86c 100644
--- a/test/streamly-tests.cabal
+++ b/test/streamly-tests.cabal
@@ -411,7 +411,7 @@ test-suite Data.Stream.Rate
     buildable: True
   else
     buildable: False
-  if flag(use-streamly-core)
+  if flag(use-streamly-core) || !flag(include-flaky-tests)
     buildable: False
 
 -- XXX Rename to MutByteArray.Unbox
@@ -628,7 +628,7 @@ test-suite Prelude.Rate
     buildable: True
   else
     buildable: False
-  if flag(use-streamly-core)
+  if flag(use-streamly-core) || !flag(include-flaky-tests)
     buildable: False
 
 test-suite Prelude.Serial

From 4963bca222891df7cebda4273d098ad040549ebd Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Wed, 6 May 2026 01:43:06 +0530
Subject: [PATCH 09/10] Cleanup and fix the circle-ci config file

install gcc and bintuils separately. they are not found by default
anymore.
---
 .circleci/config.yml | 40 ++++++++--------------------------------
 1 file changed, 8 insertions(+), 32 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index a5718b5526..d022a12526 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -12,7 +12,7 @@ env: &env
       # ------------------------------------------------------------------------
       # GHC_OPTIONS: "-Werror"
       # For updating see: https://downloads.haskell.org/~ghcup/
-      GHCUP_VERSION: 0.1.20.0
+      GHCUP_VERSION: latest
       CABAL_REINIT_CONFIG: "y"
       LC_ALL: "C.UTF-8"
 
@@ -44,7 +44,7 @@ env: &env
       # ------------------------------------------------------------------------
       # Where to find the required tools
       # ------------------------------------------------------------------------
-      PATH: /sbin:/usr/sbin:/bin:/usr/bin
+      PATH: /sbin:/usr/sbin:/bin:/usr/bin:/usr/local/bin
 
       # ------------------------------------------------------------------------
       # Location of packcheck.sh (the shell script invoked to perform CI tests ).
@@ -57,7 +57,7 @@ env: &env
       # If you have not committed packcheck.sh in your repo at PACKCHECK
       # then it is automatically pulled from this URL.
       PACKCHECK_GITHUB_URL: "https://raw.githubusercontent.com/composewell/packcheck"
-      PACKCHECK_GITHUB_COMMIT: "dd6862df527f317fd4987afa523fba3f4fde7e19"
+      PACKCHECK_GITHUB_COMMIT: "157310b35907e93b9c5c69e6bdcad9ab6296260e"
 
 executors:
   amd64-executor:
@@ -91,11 +91,7 @@ preinstall: &preinstall
         apt-get install -y zlib1g-dev
 
         # For ghcup to install ghc
-        if test -n "$GHCUP_VERSION"
-        then
-          apt-get install -y gcc
-          apt-get install -y g++
-        fi
+        apt-get install -y build-essential
 
         # libgmp required by ghc for linking
         apt-get install -y libgmp-dev
@@ -146,24 +142,7 @@ save: &save
 #-----------------------------------------------------------------------------
 
 jobs:
-  cabal-ghc-8_6_5:
-      <<: *env
-      executor: amd64-executor
-      steps:
-        - checkout
-        - *restore
-        - *preinstall
-        - run:
-            environment:
-              GHCVER: "8.6.5"
-              CABALVER: "3.6.2.0"
-              CABAL_PROJECT: "cabal.project"
-              DISABLE_SDIST_BUILD: "yes"
-              CABAL_BUILD_OPTIONS: "--flag debug --flag -opt"
-            command: |
-              bash -c "$PACKCHECK cabal"
-        - *save
-  cabal-ghc-9_8_1-docspec:
+  cabal-ghc-9_14_1-docspec:
       <<: *env
       executor: amd64-executor
       steps:
@@ -172,8 +151,7 @@ jobs:
         - *preinstall
         - run:
             environment:
-              GHCVER: "9.8.1"
-              CABALVER: "3.10.1.0"
+              GHCVER: "9.14.1"
               CABAL_PROJECT: "cabal.project.doctest"
               DISABLE_SDIST_BUILD: "y"
               DISABLE_TEST: "y"
@@ -212,9 +190,7 @@ workflows:
   version: 2
   build:
     jobs:
-      #- cabal-ghc-8_6_5:
-      #    name: 8.6.5-debug-unoptimized
-      - cabal-ghc-9_8_1-docspec:
-          name: ghc-9.8.1-docspec
+      - cabal-ghc-9_14_1-docspec:
+          name: ghc-9.14.1-docspec
       - hlint-trailing-spaces:
           name: hlint and trailing spaces

From 9cc22a83460c7f0925d2c1b703363a678df89c9f Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra@composewell.com>
Date: Wed, 6 May 2026 05:01:23 +0530
Subject: [PATCH 10/10] Fix docspec for GHC 9.14.1

---
 src/Streamly/Internal/Data/Stream/MkType.hs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/Streamly/Internal/Data/Stream/MkType.hs b/src/Streamly/Internal/Data/Stream/MkType.hs
index a11df53ed0..8415d655c0 100644
--- a/src/Streamly/Internal/Data/Stream/MkType.hs
+++ b/src/Streamly/Internal/Data/Stream/MkType.hs
@@ -516,9 +516,11 @@ flattenDec (ma:mas) = do
 -- unZipStream (ZipStream strm) = strm
 -- deriving instance IsList (ZipStream Identity a)
 -- deriving instance a ~
---                   GHC.Types.Char => IsString (ZipStream Identity a)
--- deriving instance GHC.Classes.Eq a => Eq (ZipStream Identity a)
--- deriving instance GHC.Classes.Ord a => Ord (ZipStream Identity a)
+--                   GHC.Internal.Types.Char => IsString (ZipStream Identity a)
+-- deriving instance GHC.Internal.Classes.Eq a => Eq (ZipStream Identity
+--                                                              a)
+-- deriving instance GHC.Internal.Classes.Ord a => Ord (ZipStream Identity
+--                                                                a)
 -- instance Show a => Show (ZipStream Identity a)
 --     where {{-# INLINE show #-}; show (ZipStream strm) = show strm}
 -- instance Read a => Read (ZipStream Identity a)