diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f65506f..2ed5264 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -1,20 +1,20 @@
-# packcheck-0.7.0
+# packcheck-0.7.1
 # You can use any of the options supported by packcheck as environment
 # variables here.  See https://github.com/composewell/packcheck for all
 # options and their explanation.
 
-name: packcheck
+name: TEST
 
 #-----------------------------------------------------------------------------
 # Events on which the build should be triggered
 #-----------------------------------------------------------------------------
 
 on:
+  workflow_dispatch:
+  pull_request:
   push:
     branches:
       - master
-  pull_request:
-
 
 #-----------------------------------------------------------------------------
 # Build matrix
@@ -22,158 +22,492 @@ on:
 
 jobs:
   build:
-    name: ${{ matrix.name }}
+    name: >-
+      ${{ matrix.runner }}
+      ${{ matrix.command }}
+      ${{ matrix.ghc_version }}
+      ${{ matrix.name }}
     env:
+      # ------------------------------------------------------------------------
+      # What to build
+      # ------------------------------------------------------------------------
+      # DISABLE_TEST: "y"
+      # DISABLE_BENCH: "y"
+      # DISABLE_DOCS: "y"
+      # DISABLE_SDIST_BUILD: "y"
+      # DISABLE_SDIST_GIT_CHECK: "y"
+      # DISABLE_DIST_CHECKS: "y"
+
+      # ------------------------------------------------------------------------
+      # Selecting tool versions
+      # ------------------------------------------------------------------------
+      # For updating see: https://downloads.haskell.org/~ghcup/
+      #GHCUP_VERSION: 0.1.50.2
+
+      # ------------------------------------------------------------------------
+      # cabal options
+      # ------------------------------------------------------------------------
+
+      # CABAL_BUILD_OPTIONS="-j1"
+      # Enable the above option if you:
+      # 1. want logs in serial order to be able to correlate them better.
+      #
+      # 2. run into memory issues due to Build paralellism. We need to
+      # have sufficient per CPU memory, if not we can use a lower -j
+      # option; cabal default is ncpus.
+      #
+      # Currently (2026-03-12) from packcheck output we see:
+      # Linux: 15GB, 4 cpus
+      # macOS: 7GB, 3 cpus
+      # Windows: 16GB, 4 cpus
+
+      # ------------------------------------------------------------------------
+      # stack options (if using stack builds)
+      # ------------------------------------------------------------------------
+      # Note requiring a specific version of stack using STACKVER may fail due to
+      # github API limit while checking and upgrading/downgrading to the specific
+      # version.
+      #STACKVER: "1.6.5"
+      #STACK_UPGRADE: "y"
+
       # ------------------------------------------------------------------------
       # Common options
       # ------------------------------------------------------------------------
-      # GHC_OPTIONS: "-Werror"
-      GHCUP_VERSION: 0.1.20.0
-      DOCSPEC_URL: https://github.com/phadej/cabal-extras/releases/download/cabal-docspec-0.0.0.20210111/cabal-docspec-0.0.0.20210111.xz
-      DOCSPEC_OPTIONS: "--timeout 60"
-      CABAL_REINIT_CONFIG: y
-      LC_ALL: C.UTF-8
 
-      STACK_UPGRADE: "y"
+      # Subdir
+      SUBDIR: ${{ matrix.subdir }}
 
-      CABAL_CHECK_RELAX: y
-      CABAL_HACKAGE_MIRROR: hackage.haskell.org:http://hackage.fpcomplete.com
+      # If this option is enabled packcheck clears out the environment
+      # and only uses the options explicitly set on the command line,
+      # implicit environment won't affect the build. if you find this
+      # annoying comment this.
+      CHECK_ENV: "y"
 
-      PACKCHECK: "./packcheck.sh"
+      # NOTE: by capturing the options in env variables here quotes
+      # are presrved, if we expand them directly into the script
+      # quotes are lost.
+      #
+      # WARNING! you cannot use comments in this
+      COMMON_OPTIONS: >-
+        LC_ALL=C.UTF-8
+        BUILD_PREFETCH=y
+        GHCUP_VERSION=latest
+        GHCVER=${{ matrix.ghc_version }}
+
+      # WARNING! you cannot use comments in this
+      CABAL_OPTIONS: >-
+        CABAL_REINIT_CONFIG=y
+        CABAL_CHECK_RELAX=y
+
+      MATRIX_OPTIONS: ${{ matrix.pack_options }}
+
+      # ------------------------------------------------------------------------
+      # Location of packcheck.sh (the shell script invoked to perform CI tests ).
+      # ------------------------------------------------------------------------
+      # You can either commit the packcheck.sh script in your repo root or
+      # you can use it by specifying the PACKCHECK_REPO_URL option.
+      # 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: "7c4e1ab7a59b5ed6e92cfd0da67460a6116be4ac"
-
-      BUILD: ${{ matrix.build }}
-      GHCVER: ${{ matrix.ghc_version }}
-      #RESOLVER: ${{ matrix.resolver }}
-      CABAL_BUILD_OPTIONS: >-
-        -f drinkery
-        -f conduit
-        -f pipes
-        -f machines
-        -f streaming
-        ${{ matrix.cabal_build_options }}
-      CABAL_PROJECT: ${{ matrix.cabal_project }}
-      DISABLE_DOCS: ${{ matrix.disable_docs }}
-      #DISABLE_SDIST_BUILD: ${{ matrix.disable_sdist_build }}
-      #DISABLE_SDIST_BUILD: "y"
-      HLINT_VERSION: 3.6.1
-      HLINT_OPTIONS: ${{ matrix.hlint_options }}
-      HLINT_TARGETS: ${{ matrix.hlint_targets }}
+      PACKCHECK_GITHUB_COMMIT: "b91dd7daf50d91047ca8c1cce47e8634e34dfcbc"
 
+    # ubuntu seems to have better support than debian on CI systems
     runs-on: ${{ matrix.runner }}
+    #continue-on-error: ${{ matrix.ignore_error }}
     strategy:
       fail-fast: false
       matrix:
+
+        # The order of jobs is important to optimize fail-fast, if
+        # fail-fast is set to true.
+
+        # This section is to order the important jobs first especially for
+        # "fail-fast" so that these are the ones started first.
+        #name:
+        #  - ci
+
+        # IMPORTANT NOTE:
+        # If runner, command, ghc version are identical then the name of
+        # CI is used to distinguish the cache key.
+
+        # The reason we have an explicit "name" field in the following
+        # entries is to force an additional config instead of adding to
+        # an existing config while adding additional configs.
+        # Look at <https://docs.github.com/en/free-pro-team@latest/actions/reference/workflow-syntax-for-github-actions#jobsjob_idstrategymatrix>
+        # for more info about adding matrix elements.
+        # Adding any element to the list will increase the number of matrix
+        # elements proportional to the cross product.
+
         include:
-          - name: 9.10.1-Werror
-            ghc_version: 9.10.1
-            build: cabal
+
+          #- name: ci
+          #  runner: ubuntu-latest
+          #  command: cabal
+          #  ghc_version: head
+          #  # The URL may change, to find a working URL go to https://gitlab.haskell.org/ghc/ghc/-/jobs/
+          #  # Find a debian10/11/12 job, click on a passed/failed status, at the
+          #  # end of the output you will find the tar.xz name, put that tar
+          #  # name after "raw/", and put the job name after "job=".
+          #  # Also see https://github.com/mpickering/ghc-artefact-nix/blob/master/gitlab-artifact.nix
+          #  #
+          #  # May also use ghcup for installing ghc head version, use the
+          #  # version "LatestNightly", and the following config:
+          #  # ghcup config add-release-channel https://ghc.gitlab.haskell.org/ghcup-metadata/ghcup-nightlies-0.0.7.yaml
+          #  # WARNING! cannot use # comments inside pack_options.
+          #  pack_options: >-
+          #    GHCUP_GHC_OPTIONS="-u https://gitlab.haskell.org/ghc/ghc/-/jobs/artifacts/master/raw/ghc-x86_64-linux-deb10-int_native-validate.tar.xz?job=x86_64-linux-deb10-int_native-validate"
+          #    CABAL_PROJECT=cabal.project.ghc-head
+          #    DISABLE_SDIST_BUILD="y"
+
+          - name: ci
             runner: ubuntu-latest
-            cabal-version: 3.10.2.0
-            cabal_project: cabal.project.Werror
+            command: cabal
+            ghc_version: 9.14.1
+            # WARNING! cannot use # comments inside pack_options.
+            # CABAL_BUILD_OPTIONS="-f drinkery -f conduit -f pipes -f machines -f streaming"
+            pack_options: >-
+              CABAL_PROJECT=cabal.project.user
 
-          - name: 9.8.1-Werror
-            ghc_version: 9.8.1
-            build: cabal
+          - name: bench-runner
             runner: ubuntu-latest
-            cabal-version: 3.10.2.0
-            cabal_project: cabal.project.Werror
+            command: cabal
+            ghc_version: 9.12.4
+            subdir: bench-runner
+            pack_options: >-
+              CABAL_PROJECT=cabal.project.user
 
-          - name: hlint
-            build: hlint
-            hlint_options: "lint"
-            hlint_targets: "lib Benchmarks"
+          - name: ci
             runner: ubuntu-latest
-            cabal-version: 3.2
-            cabal_project: cabal.project.user
+            command: cabal
+            ghc_version: 9.12.4
+            # Removed "-f pipes" and machines as the build was failing with heap overflow
+            pack_options: >-
+              CABAL_PROJECT=cabal.project.user
+              CABAL_BUILD_OPTIONS="-f drinkery -f conduit -f streaming"
 
-          - name: 9.6.3-macos
-            runner: macos-latest
-            ghc_version: 9.6.3
-            build: cabal
-            cabal-version: 3.10.1.0
-            cabal_project: cabal.project.user
+          - name: Werror
+            runner: ubuntu-latest
+            command: cabal
+            ghc_version: 9.10.3
+            # WARNING! cannot use # comments inside pack_options.
+            pack_options: >-
+              CABAL_PROJECT=cabal.project.Werror
+              CABAL_BUILD_OPTIONS="-f drinkery -f conduit -f pipes -f machines -f streaming"
 
-          - name: 9.4.4-no-fusion-plugin
+          - name: ci
             runner: ubuntu-latest
-            ghc_version: 9.4.4
-            build: cabal
-            cabal-version: 3.8.1.0
-            cabal_project: cabal.project.user
-            cabal_build_options: -f no-fusion-plugin
+            command: cabal
+            ghc_version: 9.8.4
+            # WARNING! cannot use # comments inside pack_options.
+            pack_options: >-
+              CABAL_PROJECT=cabal.project.user
+              CABAL_BUILD_OPTIONS="-f drinkery -f conduit -f pipes -f machines -f streaming"
 
-          - name: 9.4.4
+          - name: ci
+            runner: macos-latest
+            command: cabal
+            ghc_version: 9.6.3
+            # WARNING! cannot use # comments inside pack_options.
+            pack_options: >-
+              CABAL_PROJECT=cabal.project.user
+              CABAL_BUILD_OPTIONS="-f drinkery -f conduit -f pipes -f machines -f streaming"
+
+          - name: no-fusion-plugin
             runner: ubuntu-latest
+            command: cabal
             ghc_version: 9.4.4
-            build: cabal
-            cabal-version: 3.8.1.0
-            cabal_project: cabal.project.user
+            pack_options: >-
+              CABAL_PROJECT=cabal.project.user
+              CABAL_BUILD_OPTIONS="-f drinkery -f conduit -f pipes -f machines -f streaming -f no-fusion-plugin"
 
-          - name: 9.2.7
+          - name: ci
             runner: ubuntu-latest
-            ghc_version: 9.2.7
-            build: cabal
-            cabal-version: 3.6
-            cabal_project: cabal.project.user
+            command: cabal
+            ghc_version: 9.2.8
+            pack_options: >-
+              CABAL_PROJECT=cabal.project.user
+              CABAL_BUILD_OPTIONS="-f drinkery -f conduit -f pipes -f machines -f streaming"
 
-          - name: 8.10.7
+          - name: ci
             runner: ubuntu-latest
+            command: cabal
             ghc_version: 8.10.7
-            build: cabal
-            cabal-version: 3.2
-            cabal_project: cabal.project.user
-            disable_docs: y
+            # WARNING! cannot use # comments inside pack_options.
+            pack_options: >-
+              CABAL_PROJECT=cabal.project.user
+              DISABLE_DOCS=y
+              CABAL_BUILD_OPTIONS="-f drinkery -f conduit -f pipes -f machines -f streaming"
 
-          - name: 8.8.4
+          - name: ci
             runner: ubuntu-latest
-            ghc_version: 8.8.4
-            build: cabal
-            cabal-version: 3.2
-            cabal_project: cabal.project.user
-            disable_docs: y
+            command: hlint
+            # WARNING! cannot use # comments inside pack_options.
+            pack_options: >-
+              HLINT_VERSION=3.6.1
+              HLINT_OPTIONS="lint"
+              HLINT_TARGETS="lib Benchmarks"
 
-          - name: 8.6.5
-            runner: ubuntu-latest
-            ghc_version: 8.6.5
-            build: cabal
-            cabal-version: 3.2
-            cabal_project: cabal.project.user
-            disable_docs: y
+#-----------------------------------------------------------------------------
+# Usually you do not need to change anything below, this is generic code for
+# caching and running packcheck on Linux/Mac/Windows.
+#-----------------------------------------------------------------------------
 
     steps:
-    - uses: actions/checkout@v2
 
-    - uses: actions/cache@v4
-      name: Restore cache
+    - name: Optimize Windows Runner Environment
+      if: runner.os == 'Windows'
+      shell: powershell
+      run: |
+        # Enable long paths.  Sometimes failures occur due to path
+        # length limitation.
+        Set-ItemProperty -Path 'HKLM:\System\CurrentControlSet\Control\FileSystem' -Name 'LongPathsEnabled' -value 1
+
+        # Cache saving is very slow on Windows, it could be due to tar,
+        # or the compression program or the file system. Changing the
+        # compression level of zstd does not help. We are also not able to pick
+        # another tar program by changing the path, tar is picked up by the
+        # cache action itself.
+
+        # This does not seem to make much difference.
+        # Disable Windows Defender to speed up IO/Tar operations
+        Set-MpPreference -DisableRealtimeMonitoring $true
+
+    - uses: actions/checkout@v4
+
+    # This should happen before cache restore.
+    - name: Remove ~/.ghcup symlink (non-Windows)
+      if: runner.os != 'Windows'
+      run: |
+        rm -f ~/.ghcup
+
+    # See the "cabal path" output in the CI logs to tweak the cache
+    # locations.
+
+    # Shared by all tests, all platforms
+    - name: Restore hackage package index (non-Windows)
+      id: restore-hackage
+      uses: actions/cache/restore@v4
+      if: runner.os != 'Windows'
       with:
         path: |
-          ~/.local
-          ~/.cabal
+            ~/.cache/cabal/packages
+        key: cabal-hackage-index-non-windows
+
+    # GHC is not test/options specific
+    - name: Restore ghcup and ghc (non-Windows)
+      id: restore-ghcup
+      uses: actions/cache/restore@v4
+      if: runner.os != 'Windows'
+      with:
+        path: |
+          ~/.ghcup
+        key: ghc-${{ matrix.ghc_version }}-v${{ matrix.ghc_salt }}-${{ matrix.runner }}
+
+    # GHC is not test/options specific
+    #- name: Restore ghcup and ghc (Windows)
+    #  id: restore-ghcup-win
+    #  uses: actions/cache/restore@v4
+    #  if: runner.os == 'Windows'
+    #  with:
+    #    path: |
+    #      C:/ghcup
+    #    key: ghc-${{ matrix.ghc_version }}-v${{ matrix.ghc_salt }}-${{ matrix.runner }}
+
+    # XXX If we want to invalidate the cache on resolver change we
+    # should use a separate cache for stack as it should be keyed on
+    # resolver as well. But that requires resolver as a matrix element
+    # and then copied to pack_options from there, needs some work. It
+    # should be fine as resolver minor version change can only increase
+    # the cache size.
+    # Deps are test/options specific
+    - name: Restore build dependencies (non-Windows)
+      id: restore-deps-nonwin
+      uses: actions/cache/restore@v4
+      if: runner.os != 'Windows'
+      with:
+        # cabal: ~/.local/bin, ~/.local/state/cabal
+        # ~/.cache/cabal/packages can be cached, but will increase the
+        # cache size. But can save the "cabal update" time.
+        path: |
+          ~/.local/bin
+          ~/.local/state/cabal
           ~/.stack
-          .stack-work
-        key: ${{ runner.os }}-${{ matrix.name }}
+        key: ${{ matrix.command }}-deps-ghc-${{ matrix.ghc_version }}-v${{ matrix.ghc_salt }}-${{ matrix.runner }}-${{ matrix.name }}
+
+    # Deps are test/options specific
+    - name: Restore build dependencies, hackage index, local/bin (Windows)
+      id: restore-deps-win
+      uses: actions/cache/restore@v4
+      if: runner.os == 'Windows'
+      with:
+        path: |
+          C:/cabal
+        key: ${{ matrix.command }}-deps-ghc-${{ matrix.ghc_version }}-v${{ matrix.ghc_salt }}-${{ matrix.runner }}-${{ matrix.name }}
 
     - name: Download packcheck
+      # on windows-latest GitHub Actions defaults to PowerShell
+      shell: bash
       run: |
-        # If a custom stack-yaml is specified, replace the default with that
-        #if test -e "$STACK_YAML"; then rm -f stack.yaml && ln -sv $STACK_YAML stack.yaml; else true; fi
-        #unset STACK_YAML
-
-        if test ! -e "$PACKCHECK"
-        then
-          if test -z "$PACKCHECK_GITHUB_COMMIT"
+        download_one () {
+          if test ! -e "$1"
           then
-              die "PACKCHECK_GITHUB_COMMIT is not specified."
+            if test -z "$PACKCHECK_GITHUB_COMMIT"
+            then
+            die "Downloading [$1]: PACKCHECK_GITHUB_COMMIT env var is not specified."
+            fi
+            PACKCHECK_URL_PREFIX=${PACKCHECK_GITHUB_URL}/${PACKCHECK_GITHUB_COMMIT}
+            curl --fail -sLO ${PACKCHECK_URL_PREFIX}/$1 || exit 1
+            chmod +x "$1"
+          elif test ! -x "$1"
+          then
+              chmod +x $1
           fi
-          PACKCHECK_URL=${PACKCHECK_GITHUB_URL}/${PACKCHECK_GITHUB_COMMIT}/packcheck.sh
-          curl --fail -sL -o "$PACKCHECK" $PACKCHECK_URL || exit 1
-          chmod +x $PACKCHECK
-        elif test ! -x "$PACKCHECK"
-        then
-            chmod +x $PACKCHECK
+        }
+        if test -n "$SUBDIR"; then
+          cd "$SUBDIR"
         fi
+        download_one packcheck.sh
 
-    - name: Run packcheck
+    # Store the function in a file so that it can be reused across multiple
+    # steps.
+    - name: Setup packcheck
+      shell: bash
       run: |
-          bash -c "$PACKCHECK $BUILD"
+        if test -n "$SUBDIR"; then
+          rm -f cabal.project
+          cd "$SUBDIR"
+        fi
+        cat << 'EOF' > packcheck-setup.sh
+        setup_packcheck_args() {
+          ARGS="${{ matrix.command }} $COMMON_OPTIONS"
+          if test "${{ matrix.command }}" = "cabal"; then
+            ARGS="$ARGS $CABAL_OPTIONS"
+          fi
+
+          # Caution: do not use matrix.pack_options directly here
+          # quotes will get stripped.
+          ARGS="$ARGS $MATRIX_OPTIONS"
+          PATH_VAR=/bin:/usr/bin:/sbin:/usr/sbin
+
+          case "$(uname)" in
+            Linux)
+              export GHCUP_INSTALL_BASE_PREFIX=$HOME
+              # Access usr/local seems to be much slower on github
+              #PATH_VAR="$PATH_VAR:/usr/local/.ghcup/bin"
+              ;;
+            CYGWIN*|MINGW*|MSYS*)
+              for var in APPDATA CABAL_DIR; do
+                val="${!var}"
+                [ -n "$val" ] && ARGS="$ARGS $var=\"$(cygpath -u "$val")\""
+              done
+              ARGS="$ARGS CABAL_BUILDDIR=\"/c/b\" WINVER=$WINVER"
+              ARGS="$ARGS NUMBER_OF_PROCESSORS=$NUMBER_OF_PROCESSORS"
+              ARGS="$ARGS PROCESSOR_IDENTIFIER=\"$PROCESSOR_IDENTIFIER\""
+              PATH_VAR="$PATH_VAR:/c/ghcup:/c/Program Files/7-Zip:/mingw64/bin"
+              ;;
+          esac
+          ARGS="$ARGS PATH=\"$PATH_VAR\""
+          export ARGS
+        }
+        EOF
+
+    - name: Run packcheck (dependencies only)
+      id: deps-only
+      # Check the relevant step based on the runner OS
+      if: |
+        (runner.os != 'Windows' && steps.restore-deps-nonwin.outputs.cache-hit != 'true') ||
+        (runner.os == 'Windows' && steps.restore-deps-win.outputs.cache-hit != 'true')
+      shell: bash
+      run: |
+        if test -n "$SUBDIR"; then
+          cd "$SUBDIR"
+        fi
+        source packcheck-setup.sh
+        setup_packcheck_args
+        eval "./packcheck.sh $ARGS BUILD_DEPS_ONLY=y"
+
+    - name: Save hackage package index (non-Windows)
+      uses: actions/cache/save@v4
+      if: always() && steps.deps-only.outcome == 'success' && runner.os != 'Windows' && steps.restore-hackage.outputs.cache-hit != 'true'
+      with:
+        path: ~/.cache/cabal/packages
+        key: cabal-hackage-index-non-windows
+
+    - name: Save ghcup and ghc (non-Windows)
+      uses: actions/cache/save@v4
+      if: always() && steps.deps-only.outcome == 'success' && runner.os != 'Windows' && steps.restore-ghcup.outputs.cache-hit != 'true'
+      with:
+        path: ~/.ghcup
+        key: ghc-${{ matrix.ghc_version }}-v${{ matrix.ghc_salt }}-${{ matrix.runner }}
+
+    # On Windows, ghc restore step takes 2-3 minutes whereas installing
+    # GHC takes less than 2 minutes. On top of this saving the ghc cache
+    # takes 7 minutes. So this does not make sense.
+    #- name: Save ghcup and ghc (Windows)
+    #  uses: actions/cache/save@v4
+    #  if: always() && steps.deps-only.outcome == 'success' && runner.os == 'Windows' && steps.restore-ghcup-win.outputs.cache-hit != 'true'
+    #  with:
+    #    path: |
+    #      C:/ghcup
+    #    key: ghc-${{ matrix.ghc_version }}-v${{ matrix.ghc_salt }}-${{ matrix.runner }}
+
+    # Deps are test/options specific, hence, matrix.name in the key
+    - name: Save build dependencies (non-Windows)
+      uses: actions/cache/save@v4
+      if: always() && steps.deps-only.outcome == 'success' && runner.os != 'Windows' && steps.restore-deps-nonwin.outputs.cache-hit != 'true'
+      with:
+        path: |
+          ~/.local/bin
+          ~/.local/state/cabal
+          ~/.stack
+        key: ${{ matrix.command }}-deps-ghc-${{ matrix.ghc_version }}-v${{ matrix.ghc_salt }}-${{ matrix.runner }}-${{ matrix.name }}
+
+    # hackage package index is part of C:/cabal
+    # Deps are test/options specific, hence, matrix.name in the key
+    # Add if needed ~/AppData/Roaming/local
+    - name: Save build dependencies (Windows)
+      uses: actions/cache/save@v4
+      if: always() && steps.deps-only.outcome == 'success' && runner.os == 'Windows' && steps.restore-deps-win.outputs.cache-hit != 'true'
+      with:
+        path: |
+          C:/cabal
+        key: ${{ matrix.command }}-deps-ghc-${{ matrix.ghc_version }}-v${{ matrix.ghc_salt }}-${{ matrix.runner }}-${{ matrix.name }}
+
+    - name: Run packcheck (final build)
+      shell: bash
+      run: |
+        if test -n "$SUBDIR"; then
+          cd "$SUBDIR"
+        fi
+        source packcheck-setup.sh
+        setup_packcheck_args
+        eval "./packcheck.sh $ARGS BUILD_PACKAGE_ONLY=y"
+
+    # Enable for debugging, this itself takes 50 sec on Windows, in packcheck
+    # build which is tiny.
+    #- name: Check cache locations
+    #  shell: bash
+    #  run: |
+    #    # We want to see if any cache paths are symlinks; e.g. on github
+    #    # ~/.ghcup is a pre-existing symlink to /usr/local.
+    #    if [ "$RUNNER_OS" == "Windows" ]; then
+    #      # Convert Windows paths to Unix-style for Bash
+    #      APPDATA_UNIX=$(cygpath "$APPDATA")
+    #      list="$APPDATA_UNIX/local C:/ghcup C:/cabal"
+    #    else
+    #      list="$HOME/.local/bin $HOME/.local/state/cabal $HOME/.ghcup $HOME/.stack"
+    #    fi
+
+    #    for dir in $list; do
+    #      # macOS does not have --no-dereference option
+    #      if [ -L "$dir" ]; then
+    #        echo "$dir is a symlink -> $(readlink $dir)"
+    #      elif [ -d "$dir" ]; then
+    #        du -sh "$dir" 2>/dev/null || echo "$dir permission denied"
+    #      else
+    #        echo "$dir missing or not a dir"
+    #      fi
+    #    done
+    #    echo
+    #    #ls -ld $list 2>/dev/null || true
+    #    ls -al $list 2>/dev/null || true
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..48a004c
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+dist-newstyle
diff --git a/.packcheck.ignore b/.packcheck.ignore
index 71a32fe..6b6d362 100644
--- a/.packcheck.ignore
+++ b/.packcheck.ignore
@@ -1,4 +1,5 @@
 .github/workflows/build.yml
+.gitignore
 .packcheck.ignore
 Benchmarks/ListT.hs
 Benchmarks/ListTransformer.hs
@@ -7,5 +8,7 @@ Benchmarks/SimpleConduit.hs
 appveyor.yml
 cabal.project.user
 cabal.project.Werror
-default.nix
-stack.yaml
+flake.lock
+flake.nix
+packages.nix
+sources.nix
diff --git a/Changelog.md b/Changelog.md
index f312042..b599d1d 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,3 +1,7 @@
+## 0.4.1
+
+* Support streamly-core-0.3.0 and streamly-0.11.0
+
 ## 0.4.0
 
 * Add different streaming libraries under individual flags
diff --git a/README.md b/README.md
index c685246..9e9b309 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@
 This package provides micro-benchmarks to measure and compare the
 performance of various streaming implementations in Haskell.
 
-We have taken due to care to make sure that we are
+We have taken due care to make sure that we are
 benchmarking correctly and fairly. See [the notes on correct
 benchmarking](docs/benchmarking-notes.md).
 
diff --git a/appveyor.yml b/appveyor.yml
index f54f8b6..7cbbc60 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,8 +1,12 @@
-# packcheck-0.4.2
+# packcheck-0.7.1
 # You can use any of the options supported by packcheck as environment
 # variables here.  See https://github.com/composewell/packcheck for all
 # options and their explanation.
 
+#branches:
+#  only:
+#    - master
+
 environment:
     # ------------------------------------------------------------------------
     # Global options, you can use these per build as well
@@ -11,42 +15,34 @@ environment:
     # ------------------------------------------------------------------------
     # Common options
     # ------------------------------------------------------------------------
-    # GHC_OPTIONS: "-Werror"
     CABAL_REINIT_CONFIG: "y"
     LC_ALL: "C.UTF-8"
 
+    # ------------------------------------------------------------------------
+    # How to build
+    # ------------------------------------------------------------------------
+    #
+    GHCUP_VERSION: "0.1.50.2"
+    GHCVER: "9.10.3"
+    #CABALVER: "3.10.3.0"
+
     # ------------------------------------------------------------------------
     # What to build
     # ------------------------------------------------------------------------
     # DISABLE_TEST: "y"
     # DISABLE_BENCH: "y"
     # DISABLE_DOCS: "y"
-    DISABLE_SDIST_BUILD: "y"
     # DISABLE_DIST_CHECKS: "y"
-
-    # ------------------------------------------------------------------------
-    # stack options
-    # ------------------------------------------------------------------------
-    # Note requiring a specific version of stack using STACKVER may fail due to
-    # github API limit while checking and upgrading/downgrading to the specific
-    # version.
-    #STACKVER: "1.6.5"
-    STACK_UPGRADE: "y"
-    RESOLVER: "lts-21.25"
-    STACK_ROOT: "c:\\sr"
+    # DISABLE_SDIST_BUILD: "y"
+    # Note: these require the "diff" utility.
+    # DISABLE_SDIST_GIT_CHECK: "y"
+    DISABLE_SDIST_PROJECT_CHECK: "y"
 
     # ------------------------------------------------------------------------
     # cabal options
     # ------------------------------------------------------------------------
     CABAL_CHECK_RELAX: "y"
-    CABAL_NO_SANDBOX: "y"
-    CABAL_HACKAGE_MIRROR: "hackage.haskell.org:http://hackage.fpcomplete.com"
-
-    # ------------------------------------------------------------------------
-    # Where to find the required tools
-    # ------------------------------------------------------------------------
-    PATH: "%PATH%;%APPDATA%\\local\\bin"
-    LOCAL_BIN: "%APPDATA%\\local\\bin"
+    #CABAL_PROJECT: "cabal.project"
 
     # ------------------------------------------------------------------------
     # Location of packcheck.sh (the shell script invoked to perform CI tests ).
@@ -59,31 +55,33 @@ environment:
     # If you have not committed packcheck.sh in your repo at PACKCHECK_LOCAL_PATH
     # then it is automatically pulled from this URL.
     PACKCHECK_GITHUB_URL: "https://raw.githubusercontent.com/composewell/packcheck"
-    PACKCHECK_GITHUB_COMMIT: "79fb4437009a7ebdada33d0493c27ee30160ec3f"
+    PACKCHECK_GITHUB_COMMIT: "3d3c94bf48f18a99271d509c1f1702d15824b1f0"
 
     # Override the temp directory to avoid sed escaping issues
     # See https://github.com/haskell/cabal/issues/5386
     TMP: "c:\\tmp"
 
+# Bump the -> version to clear the cache
+# packcheck uses "%APPDATA%\\local" to install tools like hlint etc.
+# cabal may use "%APPDATA%\\cabal" or "c:\\cabal"
+# ghcup may use "%APPDATA%\\ghcup" or "c:\\ghcup"
 cache:
-  - "%STACK_ROOT%"
-  - "%LOCAL_BIN%"
+  - "%APPDATA%\\local\\bin -> v1"
   - "%APPDATA%\\cabal"
-  - "%APPDATA%\\ghc"
-# - "%LOCALAPPDATA%\\Programs\\stack"
+  - "%LOCALAPPDATA%\\cabal"
+  - "C:\\ghcup"
+  - "C:\\cabal"
 
+# Folder where the repository is cloned.
 clone_folder: "c:\\pkg"
 build: off
 
 before_test:
-- if not exist %PACKCHECK_LOCAL_PATH% curl -sSkL -o%PACKCHECK_LOCAL_PATH% %PACKCHECK_GITHUB_URL%/%PACKCHECK_GITHUB_COMMIT%/packcheck.sh
-- if not exist %LOCAL_BIN% mkdir %LOCAL_BIN%
-- where stack.exe || curl -sSkL -ostack.zip http://www.stackage.org/stack/windows-x86_64 && 7z x stack.zip stack.exe && move stack.exe %LOCAL_BIN%
-- if defined STACKVER (stack upgrade --binary-only --binary-version %STACKVER%) else (stack upgrade --binary-only || ver > nul)
-- stack --version
+- if not exist %PACKCHECK_LOCAL_PATH% curl --fail -sSL -o%PACKCHECK_LOCAL_PATH% %PACKCHECK_GITHUB_URL%/%PACKCHECK_GITHUB_COMMIT%/packcheck.sh
 
 test_script:
-- stack setup > nul
 - for /f "usebackq tokens=*" %%i in (`where 7z.exe`) do set PATH7Z=%%i\..
 - for /f "usebackq tokens=*" %%i in (`where git.exe`) do set PATHGIT=%%i\..
-- chcp 65001 && stack exec bash -- -c "chmod +x %PACKCHECK_LOCAL_PATH%; %PACKCHECK_LOCAL_PATH% stack PATH=/usr/bin:\"%PATH7Z%\":\"%PATHGIT%\""
+- for /f "usebackq tokens=*" %%i in (`where curl.exe`) do set PATHCURL=%%i\..
+- chcp 65001
+- bash %PACKCHECK_LOCAL_PATH% cabal PATH="/usr/bin:%PATH7Z%:%PATHGIT%:%PATHCURL%"
diff --git a/bench-runner/cabal.project.user b/bench-runner/cabal.project.user
index 23c6b56..c435838 100644
--- a/bench-runner/cabal.project.user
+++ b/bench-runner/cabal.project.user
@@ -1,35 +1,35 @@
 packages: .
 
-source-repository-package
-  type: git
-  location: https://github.com/composewell/streamly.git
-  tag: 9a039b89c6b81300b2bd9c8765bf4bfa18e7c83c
-
-source-repository-package
-  type: git
-  location: https://github.com/composewell/streamly.git
-  tag: 9a039b89c6b81300b2bd9c8765bf4bfa18e7c83c
-  subdir: core
-
-source-repository-package
-  type: git
-  location: https://github.com/composewell/streamly-process.git
-  tag: c1ce40ebe84973d0c54dd27fb17e337bf9ca4a46
-
-source-repository-package
-  type: git
-  location: https://github.com/composewell/streamly-shell.git
-  tag: 070ff21fda7aab8ca45b08b330746299a91eb981
+package bench-report
+  flags: +no-charts
 
 source-repository-package
   type: git
   location: https://github.com/composewell/streamly-coreutils.git
-  tag: 051ef37a5fa399f039d0530e8d642fd79ec6aec2
+  tag: fa180060c7510c89d2767980ca6f7ec7011d04b9
 
 source-repository-package
   type: git
   location: https://github.com/composewell/bench-report.git
-  tag: a9bbaecb19eda832edf32ae274fef48895facf0b
+  tag: 4dad3ea916a950524bcfd5097fc6f0f63e645987
 
-package bench-report
-  flags: +no-charts
+-- source-repository-package
+--   type: git
+--   location: https://github.com/composewell/streamly.git
+--   tag: 9a039b89c6b81300b2bd9c8765bf4bfa18e7c83c
+-- 
+-- source-repository-package
+--   type: git
+--   location: https://github.com/composewell/streamly.git
+--   tag: 9a039b89c6b81300b2bd9c8765bf4bfa18e7c83c
+--   subdir: core
+-- 
+-- source-repository-package
+--   type: git
+--   location: https://github.com/composewell/streamly-process.git
+--   tag: c1ce40ebe84973d0c54dd27fb17e337bf9ca4a46
+-- 
+-- source-repository-package
+--   type: git
+--   location: https://github.com/composewell/streamly-shell.git
+--   tag: 070ff21fda7aab8ca45b08b330746299a91eb981
diff --git a/default.nix b/default.nix
deleted file mode 100644
index 60cce9e..0000000
--- a/default.nix
+++ /dev/null
@@ -1,102 +0,0 @@
-# CAUTION! a spelling mistake in arg string is ignored silently.
-#
-# nix-shell --argstr c2nix "--flag examples-sdl"
-
-# To use ghc-8.6.5
-# nix-shell --argstr compiler "ghc865"
-
-{
-  nixpkgs ?
-    import (builtins.fetchTarball
-      https://github.com/NixOS/nixpkgs/archive/refs/tags/22.05.tar.gz)
-        {}
-, compiler ? "ghc922"
-, c2nix ? "" # cabal2nix CLI options
-# TODO
-#, sources ? [] # e.g. [./. ./benchmark]
-#, hdeps ? [] # e.g. [time, mtl]
-#, deps ? [] # e.g. [SDL2]
-}:
-let haskellPackages =
-        if compiler == "default"
-        then nixpkgs.haskellPackages
-        else nixpkgs.haskell.packages.${compiler};
-
-    # we can possibly avoid adding our package to HaskellPackages like
-    # in the case of nix-shell for a single package?
-    mkPackage = super: pkg: path: opts: inShell:
-                let orig = super.callCabal2nixWithOptions pkg path opts {};
-                 in if inShell
-                    # Avoid copying the source directory to nix store by using
-                    # src = null.
-                    then orig.overrideAttrs (oldAttrs: { src = null; })
-                    else orig;
-
-    flags = "--benchmark" + " " + c2nix;
-
-    mkHaskellPackages = inShell:
-        haskellPackages.override {
-            # We could disbale doCheck on all like this, but it would make the
-            # whole world rebuild, we can't use the binary cache
-            #packageSetConfig = self: super: {
-            #    mkDerivation = drv: super.mkDerivation (drv // {
-            #        doCheck = false;
-            #    });
-            #};
-            overrides = self: super:
-                with nixpkgs.haskell.lib;
-                {
-                    streaming-benchmarks =
-                        mkPackage super "streaming-benchmarks"
-                            ./. flags inShell;
-
-                    streamly =
-                      nixpkgs.haskell.lib.overrideCabal
-                        (super.callHackageDirect
-                          { pkg = "streamly";
-                            ver = "0.8.3";
-                            sha256 = "sha256-A6/S/yvmOXVabVAR6x4a/XYszzeogSU4vOuyLLSGFvE=";
-                          } {})
-                        (old:
-                          { librarySystemDepends =
-                              if builtins.currentSystem == "x86_64-darwin"
-                              then [nixpkgs.darwin.apple_sdk.frameworks.Cocoa]
-                              else [];
-                            enableLibraryProfiling = false;
-                            doHaddock = false;
-                          });
-
-                    lockfree-queue =
-                      super.callHackageDirect
-                        { pkg = "lockfree-queue";
-                          ver = "0.2.4";
-                          sha256 = "1bj9agy3x0yjbscpjgn96gpnj4lvkh39spjvy3jnrr3a42v3ynw7";
-                        } {};
-
-                    #fusion-plugin =
-                    #  super.callHackageDirect
-                    #    { pkg = "fusion-plugin";
-                    #      ver = "0.2.3";
-                    #      sha256 = "073wbhdxj1sh5160blaihbzkkhabs8s71pqhag16lvmgbb7a3hla";
-                    #    } {};
-                };
-        };
-
-    hspkgs = mkHaskellPackages true;
-
-    shell = hspkgs.shellFor {
-        packages = p:
-          [ p.streaming-benchmarks
-          ];
-        doBenchmark = true;
-        shellHook = ''
-          export CABAL_DIR="$(pwd)/.cabal.nix"
-          if test -n "$PS_SHELL"
-          then
-            export PS1="$PS_SHELL\[$bldred\](nix)\[$txtrst\] "
-          fi
-        '';
-    };
-in if nixpkgs.lib.inNixShell
-   then shell
-   else (mkHaskellPackages false).streaming-benchmarks
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..d0d6dbb
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,88 @@
+{
+  "nodes": {
+    "basepkgs": {
+      "inputs": {
+        "basepkgs": "basepkgs_2",
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-darwin": "nixpkgs-darwin"
+      },
+      "locked": {
+        "lastModified": 1774694867,
+        "narHash": "sha256-Cgch0+tWHddjTUMhXCiUpu4yDGNFdMb9BAtyjv7+mTw=",
+        "ref": "refs/heads/master",
+        "rev": "0f2afe624cb0e259edbc87bdf60aabdd4cf2580a",
+        "revCount": 117,
+        "type": "git",
+        "url": "ssh://git@github.com/composewell/streamly-packages"
+      },
+      "original": {
+        "rev": "0f2afe624cb0e259edbc87bdf60aabdd4cf2580a",
+        "type": "git",
+        "url": "ssh://git@github.com/composewell/streamly-packages"
+      }
+    },
+    "basepkgs_2": {
+      "locked": {
+        "lastModified": 1774694658,
+        "narHash": "sha256-E4PwUiMKxH7paTq/6KCkudmJDTICOV4PdLOVxlWclwQ=",
+        "owner": "composewell",
+        "repo": "nixpack",
+        "rev": "57811ee9a97c48b5ec84909bc137eb57361651b0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "composewell",
+        "repo": "nixpack",
+        "rev": "57811ee9a97c48b5ec84909bc137eb57361651b0",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1774106199,
+        "narHash": "sha256-US5Tda2sKmjrg2lNHQL3jRQ6p96cgfWh3J1QBliQ8Ws=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "6c9a78c09ff4d6c21d0319114873508a6ec01655",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "6c9a78c09ff4d6c21d0319114873508a6ec01655",
+        "type": "github"
+      }
+    },
+    "nixpkgs-darwin": {
+      "locked": {
+        "lastModified": 1774106199,
+        "narHash": "sha256-US5Tda2sKmjrg2lNHQL3jRQ6p96cgfWh3J1QBliQ8Ws=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "6c9a78c09ff4d6c21d0319114873508a6ec01655",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "6c9a78c09ff4d6c21d0319114873508a6ec01655",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "basepkgs": "basepkgs",
+        "nixpkgs": [
+          "basepkgs",
+          "nixpkgs"
+        ],
+        "nixpkgs-darwin": [
+          "basepkgs",
+          "nixpkgs-darwin"
+        ]
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..f5c8ebe
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,17 @@
+{
+  description = "Streaming-benchmarks";
+
+  inputs = {
+    basepkgs.url = "git+ssh://git@github.com/composewell/streamly-packages?rev=0f2afe624cb0e259edbc87bdf60aabdd4cf2580a";
+    nixpkgs.follows = "basepkgs/nixpkgs";
+    nixpkgs-darwin.follows = "basepkgs/nixpkgs-darwin";
+  };
+
+  outputs = { self, nixpkgs, nixpkgs-darwin, basepkgs }:
+    basepkgs.nixpack.mkOutputs {
+      inherit nixpkgs nixpkgs-darwin basepkgs;
+      name = "streaming-benchmarks";
+      sources = import ./sources.nix;
+      packages = import ./packages.nix;
+    };
+}
diff --git a/packages.nix b/packages.nix
new file mode 100644
index 0000000..642a684
--- /dev/null
+++ b/packages.nix
@@ -0,0 +1,24 @@
+{ nixpkgs }:
+{
+# General packages, haskell or non-haskell will be installed in the
+# environment.
+packages =
+  with nixpkgs.pkgs;
+    [
+    ];
+
+# Haskell packages available in the nix shell, the dependencies of these
+# packages are also installed and exposed in ghc package database.
+libraries =
+with nixpkgs.haskellPackages;
+[
+  fusion-plugin streamly-core bench-report vector dlist
+];
+
+# Haskell dev packages. Install only dependencies of these in the shell,
+# do not build the packages themselves.
+dev-packages =
+  with nixpkgs.haskellPackages;
+  [ streaming-benchmarks ];
+
+}
diff --git a/sources.nix b/sources.nix
new file mode 100644
index 0000000..077ad08
--- /dev/null
+++ b/sources.nix
@@ -0,0 +1,12 @@
+{nixpack}:
+with nixpack.mkSources;
+{
+layers = [
+{
+  streaming-benchmarks = local ./.;
+  #streaming-benchmarks = localOpts ./.
+    #[]
+    #["--flags streaming"];
+}
+];
+}
diff --git a/stack.yaml b/stack.yaml
deleted file mode 100644
index 7caba7f..0000000
--- a/stack.yaml
+++ /dev/null
@@ -1,9 +0,0 @@
-resolver: lts-23.27
-packages:
-- '.'
-
-extra-deps:
-  - streamly-0.11.0
-  - streamly-core-0.3.0
-
-rebuild-ghc-options: true
diff --git a/streaming-benchmarks.cabal b/streaming-benchmarks.cabal
index 2fef636..121e658 100644
--- a/streaming-benchmarks.cabal
+++ b/streaming-benchmarks.cabal
@@ -25,7 +25,16 @@ description:
   * conduit
   * drinkery
 
-tested-with: GHC==8.8.4, GHC==8.10.4
+tested-with:
+    GHC==8.10.7
+  , GHC==9.2.8
+  , GHC==9.4.4
+  , GHC==9.6.3
+  , GHC==9.8.1
+  , GHC==9.10.3
+  , GHC==9.12.1
+  , GHC==9.14.1
+
 build-type: Simple
 extra-source-files:
   Benchmarks/VectorCommon.hs
@@ -97,11 +106,11 @@ common lib-options
     mtl                 >= 2.2.2 && < 2.4,
     random              >= 1.0   && < 2.0,
     transformers        >= 0.5.5 && < 0.7,
-    template-haskell    >= 2.14  && < 2.24
+    template-haskell    >= 2.14  && < 2.25
   if flag(use-gauge)
     build-depends:  gauge >= 0.2.4 && < 0.3
   else
-    build-depends:    tasty-bench >= 0.3 && < 0.5
+    build-depends:    tasty-bench >= 0.3 && < 0.6
                     , tasty     >= 1.4.1 && < 1.6
     mixins: tasty-bench
       (Test.Tasty.Bench as Gauge