diff --git a/.github/actions/make-snapshot/action.yml b/.github/actions/make-snapshot/action.yml
new file mode 100644
index 00000000000000..cd144d2bf6d1d0
--- /dev/null
+++ b/.github/actions/make-snapshot/action.yml
@@ -0,0 +1,79 @@
+name: 'make-snapshot'
+description: 'Make snapshot tarballs'
+inputs:
+  archname:
+    description: 'archname passed to tool/make-snapshot (e.g. snapshot-master)'
+    required: true
+  version:
+    description: 'Target Version'
+    required: false
+  shallow-since:
+    description: 'git fetch --shallow-since'
+    required: true
+    default: '2018-12-25 00:00:00'
+  fetch-branch:
+    description: 'fetch branch'
+    required: false
+  generate-tar-bz2:
+    description: 'Generate .tar.bz2'
+    required: false
+  srcdir:
+    description: 'srcdir for tool/make-snapshot. Empty = clone ruby/ruby into ./ruby.'
+    required: false
+    default: ''
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install libraries
+      run: |
+        set -x
+        sudo apt-get update -q || :
+        sudo apt-get install --no-install-recommends -q -y build-essential git bison autoconf ruby p7zip-full curl
+      shell: bash
+    - name: Checkout ruby/ruby for tool/make-snapshot
+      if: inputs.srcdir == ''
+      run: git clone --single-branch --depth=1 https://github.com/ruby/ruby ruby
+      shell: bash
+    - name: Fetch branches and notes (clone mode)
+      if: inputs.srcdir == ''
+      env:
+        SHALLOW_SINCE: ${{ inputs.shallow-since }}
+        FETCH_BRANCH: ${{ inputs.fetch-branch }}
+      run: |
+        set -x
+        cd ruby
+        git fetch --shallow-since="$SHALLOW_SINCE"
+        [ -n "$FETCH_BRANCH" ] && git fetch origin "+$FETCH_BRANCH:$FETCH_BRANCH"
+        git fetch origin '+refs/notes/commits:refs/notes/commits'
+        git fetch origin '+refs/notes/log-fix:refs/notes/log-fix'
+      shell: bash
+    - name: Fetch notes (local srcdir mode)
+      if: inputs.srcdir != ''
+      working-directory: ${{ inputs.srcdir }}
+      run: |
+        git fetch origin '+refs/notes/commits:refs/notes/commits' || :
+        git fetch origin '+refs/notes/log-fix:refs/notes/log-fix' || :
+      shell: bash
+    - name: Make snapshot
+      env:
+        ARCHNAME: ${{ inputs.archname }}
+        SRCDIR: ${{ inputs.srcdir }}
+        GENERATE_TAR_BZ2: ${{ inputs.generate-tar-bz2 }}
+        VERSION: ${{ inputs.version }}
+      run: |
+        [ -z "$SRCDIR" ] && SRCDIR=ruby
+        if [ -n "$GENERATE_TAR_BZ2" ]; then
+          ruby "$SRCDIR/tool/make-snapshot" "-archname=$ARCHNAME" -srcdir="$SRCDIR" pkg $VERSION
+        else
+          ruby "$SRCDIR/tool/make-snapshot" "-archname=$ARCHNAME" -srcdir="$SRCDIR" -packages=gzip,xz,zip pkg $VERSION
+        fi
+      shell: bash
+    - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+      with:
+        name: Packages
+        path: pkg
+    - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+      with:
+        name: Info
+        path: pkg/info
diff --git a/.github/workflows/tarball-macos.yml b/.github/workflows/tarball-macos.yml
new file mode 100644
index 00000000000000..d6552d516a7f12
--- /dev/null
+++ b/.github/workflows/tarball-macos.yml
@@ -0,0 +1,109 @@
+name: tarball-macos (reusable)
+
+on:
+  workflow_call:
+    inputs:
+      archname:
+        description: 'archname (e.g. snapshot-master, snapshot-ruby_3_3)'
+        required: true
+        type: string
+      allow-failures:
+        description: 'TEST_BUNDLED_GEMS_ALLOW_FAILURES value'
+        required: false
+        type: string
+        default: ''
+      patch-url:
+        description: 'Patch URL forwarded from workflow_dispatch'
+        required: false
+        type: string
+        default: ''
+      rebuild-homebrew-ruby:
+        description: 'Uninstall and reinstall Homebrew Ruby on macos-15-intel'
+        required: false
+        type: boolean
+        default: false
+
+jobs:
+  macos:
+    strategy:
+      matrix:
+        test_task: [check, test-bundled-gems, test-bundler-parallel]
+        os: [macos-14, macos-15]
+        include:
+          - os: macos-15-intel
+            test_task: check
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    env:
+      TEST_BUNDLED_GEMS_ALLOW_FAILURES: ${{ inputs.allow-failures }}
+    steps:
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: tar xf pkg/*.tar.xz
+      - name: Apply patch
+        run: |
+          set -x
+          curl -sSL "${RUBY_PATCH_URL}" -o ruby.patch
+          cd snapshot-*/
+          git apply ../ruby.patch
+        shell: bash
+        env:
+          RUBY_PATCH_URL: ${{ inputs.patch-url }}
+        if: inputs.patch-url != ''
+      - name: Install libraries
+        run: |
+          with_retry () {
+            "$@" || { sleep 5 && "$@"; } || { sleep 60 && "$@"; }
+          }
+          set -x
+          with_retry brew install gmp libffi openssl@1.1 zlib autoconf automake libtool readline libyaml
+      - name: Uninstall Homebrew Ruby
+        run: |
+          for formula in $(brew list 2>/dev/null | grep '^ruby'); do
+            brew uninstall --force "$formula"
+          done
+          sudo rm -rf /usr/local/lib/ruby
+        if: inputs.rebuild-homebrew-ruby && matrix.os == 'macos-15-intel'
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(sysctl -n hw.activecpu)))" >> $GITHUB_ENV
+      - name: configure
+        run: cd snapshot-*/ && ./configure --with-openssl-dir=$(brew --prefix openssl@1.1) --with-readline-dir=$(brew --prefix readline) --with-libyaml-dir=$(brew --prefix libyaml)
+      - name: make
+        run: cd snapshot-*/ && make $JOBS
+      - name: Reinstall Homebrew Ruby
+        run: brew install ruby
+        if: inputs.rebuild-homebrew-ruby && matrix.os == 'macos-15-intel' && (matrix.test_task == 'test-bundled-gems' || matrix.test_task == 'test-bundler-parallel')
+      - name: Tests
+        run: cd snapshot-*/ && make $JOBS -s ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: "-q --tty=no"
+          RUBY_DEBUG_TEST_NO_REMOTE: "1"
+      # leaked-globals since 2.7
+      - name: Leaked Globals
+        run: cd snapshot-*/ && make -s leaked-globals
+        if: matrix.test_task == 'check'
+      - name: make install without root privilege
+        run: cd snapshot-*/ && make $JOBS install DESTDIR="/tmp/destdir"
+        if: matrix.test_task == 'check'
+      - name: make install
+        run: cd snapshot-*/ && sudo make $JOBS install
+        if: matrix.test_task == 'check'
+      - name: ruby -v
+        run: /usr/local/bin/ruby -v
+        if: matrix.test_task == 'check'
+      - uses: ruby/action-slack@54175162371f1f7c8eb94d7c8644ee2479fcd375 # v3.2.2
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ matrix.os }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|${{ github.workflow }}>",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+        if: failure() && github.event_name == 'schedule'
diff --git a/.github/workflows/tarball-non-development.yml b/.github/workflows/tarball-non-development.yml
new file mode 100644
index 00000000000000..09e6b44a879fbb
--- /dev/null
+++ b/.github/workflows/tarball-non-development.yml
@@ -0,0 +1,70 @@
+name: tarball-non-development (reusable)
+
+on:
+  workflow_call: {}
+
+jobs:
+  non_development:
+    runs-on: ubuntu-24.04
+    env:
+      ruby_prefix: /tmp/ruby-snapshot
+    steps:
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: tar xf pkg/*.tar.xz
+      - name: Substitute patchlevel
+        run: |
+          set -x
+          cd snapshot-*/
+          sed -i.orig 's/^\( *# *define  *RUBY_PATCHLEVEL\)  *-.*/\1 0/' version.h
+          diff -u version.h.orig version.h || :
+          rm -f version.h.orig
+      - name: Install libraries
+        run: |
+          set -x
+          sudo apt-get update -q || :
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev bison- autoconf-
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - name: configure
+        run: cd snapshot-*/ && ./configure --prefix="${ruby_prefix}"
+      - name: make
+        run: cd snapshot-*/ && make $JOBS
+      - name: Leaked Globals
+        run: cd snapshot-*/ && make -s leaked-globals
+      - name: make install
+        run: cd snapshot-*/ && make $JOBS install
+      - name: Set PATH
+        run: echo "PATH=${ruby_prefix}/bin:$PATH" >> $GITHUB_ENV
+      - name: Check patchlevel
+        id: check-patchlevel
+        run: |
+          exec "${ruby_prefix}/bin/ruby" -vx "$0"
+          #!ruby
+          puts "RUBY_PATCHLEVEL=#{RUBY_PATCHLEVEL.inspect}"
+          abort unless RUBY_PATCHLEVEL >= 0
+        working-directory: ${{ env.ruby_prefix }}
+        continue-on-error: true
+      - name: Check LOADPATH
+        id: check-loadpath
+        run: |
+          exec ${ruby_prefix}/bin/ruby -vx "$0"
+          #!ruby
+          paths = $:.grep(/\+/)
+          pp paths
+          abort unless paths.empty?
+        working-directory: ${{ env.ruby_prefix }}
+        continue-on-error: true
+      - name: Check pathnames
+        id: check-pathnames
+        run: |
+          ! find -name '*+*' | grep +
+        working-directory: ${{ env.ruby_prefix }}
+        continue-on-error: true
+      - name: result
+        run: false
+        if: ${{ contains(steps.*.outcome, 'failure') }}
diff --git a/.github/workflows/tarball-test.yml b/.github/workflows/tarball-test.yml
new file mode 100644
index 00000000000000..49a3800e540b9f
--- /dev/null
+++ b/.github/workflows/tarball-test.yml
@@ -0,0 +1,82 @@
+name: tarball-test
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+  schedule:
+    - cron: '30 18 * * *' # Daily at 18:30 UTC
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  tarball:
+    runs-on: ubuntu-latest
+    # Cherry-pick to maintenance branches by changing only env.BRANCH below;
+    # archname / branch-label / Materialize all derive from it.
+    env:
+      BRANCH: master
+    outputs:
+      branch: ${{ env.BRANCH }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          fetch-depth: 0
+      # tool/make-snapshot derives the branch name from HEAD and looks up
+      # the upstream during ChangeLog generation. Detached checkouts
+      # (pull_request, merge_group) lack a local branch with tracking, so
+      # pin one to HEAD and connect it to the matching origin ref.
+      - name: Materialize local branch
+        run: |
+          git fetch --no-tags --depth=1 origin "+refs/heads/$BRANCH:refs/remotes/origin/$BRANCH"
+          git checkout -B "$BRANCH" HEAD
+          git branch --set-upstream-to="origin/$BRANCH" "$BRANCH"
+      - uses: ./.github/actions/make-snapshot
+        with:
+          archname: snapshot-${{ env.BRANCH }}
+          srcdir: '.'
+
+  ubuntu:
+    needs: tarball
+    uses: ./.github/workflows/tarball-ubuntu.yml
+    with:
+      archname: snapshot-${{ needs.tarball.outputs.branch }}
+      allow-failures: power_assert
+      remove-gnupg: true
+      notify-ruby-sha: true
+      branch-label: ${{ needs.tarball.outputs.branch }}
+    secrets: inherit
+
+  macos:
+    needs: tarball
+    uses: ./.github/workflows/tarball-macos.yml
+    with:
+      archname: snapshot-${{ needs.tarball.outputs.branch }}
+      allow-failures: power_assert
+    secrets: inherit
+
+  windows:
+    needs: tarball
+    uses: ./.github/workflows/tarball-windows.yml
+    with:
+      archname: snapshot-${{ needs.tarball.outputs.branch }}
+      mode: modern
+    secrets: inherit
+
+  non_development:
+    needs: tarball
+    uses: ./.github/workflows/tarball-non-development.yml
+    secrets: inherit
diff --git a/.github/workflows/tarball-ubuntu.yml b/.github/workflows/tarball-ubuntu.yml
new file mode 100644
index 00000000000000..6568942055e5f4
--- /dev/null
+++ b/.github/workflows/tarball-ubuntu.yml
@@ -0,0 +1,273 @@
+name: tarball-ubuntu (reusable)
+
+on:
+  workflow_call:
+    inputs:
+      archname:
+        description: 'archname (e.g. snapshot-master, snapshot-ruby_3_3)'
+        required: true
+        type: string
+      allow-failures:
+        description: 'TEST_BUNDLED_GEMS_ALLOW_FAILURES value'
+        required: false
+        type: string
+        default: ''
+      patch-url:
+        description: 'Patch URL forwarded from workflow_dispatch'
+        required: false
+        type: string
+        default: ''
+      apt-mode:
+        description: '"none" | "git-only" | "ruby-and-git" — controls per-test_task apt install handling'
+        required: false
+        type: string
+        default: 'none'
+      setup-host-ruby:
+        description: 'Install Ruby 3.2 via ruby/setup-ruby for test-bundled-gems'
+        required: false
+        type: boolean
+        default: true
+      remove-gnupg:
+        description: 'Forcibly remove ~/.gnupg after tests'
+        required: false
+        type: boolean
+        default: false
+      fixed-dirs-extra:
+        description: 'Create $HOME/.local/share, $HOME/.ssh on top of minimal fixed dirs'
+        required: false
+        type: boolean
+        default: true
+      ruby-bin:
+        description: 'Path to ruby for post-install version check'
+        required: false
+        type: string
+        default: '/usr/local/bin/ruby'
+      notify-ruby-sha:
+        description: 'Post ruby SHA failure notification to SIMPLER_ALERTS_URL'
+        required: false
+        type: boolean
+        default: false
+      branch-label:
+        description: 'Branch label for SIMPLER_ALERTS_URL notification. Defaults to "master".'
+        required: false
+        type: string
+        default: 'master'
+
+jobs:
+  ubuntu:
+    strategy:
+      matrix:
+        test_task: [check, test-bundler-parallel, test-bundled-gems]
+        os: [ubuntu-24.04, ubuntu-22.04]
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    env:
+      TEST_BUNDLED_GEMS_ALLOW_FAILURES: ${{ inputs.allow-failures }}
+    steps:
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: tar xf pkg/*.tar.xz
+      - name: Apply patch
+        run: |
+          set -x
+          curl -sSL "${RUBY_PATCH_URL}" -o ruby.patch
+          cd snapshot-*/
+          git apply ../ruby.patch
+        shell: bash
+        env:
+          RUBY_PATCH_URL: ${{ inputs.patch-url }}
+        if: inputs.patch-url != ''
+      - name: Install libraries (apt-mode=none)
+        run: |
+          set -x
+          sudo apt-get update -q
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev bison- autoconf-
+        if: inputs.apt-mode == 'none'
+      - name: Install libraries (apt-mode=git-only)
+        run: |
+          set -x
+          sudo apt-get update -q || :
+          # postfix `-` means `uninstall`
+          APT_INSTALL_GIT=git-
+          case "${{ matrix.test_task }}" in
+            test-bundled-gems)
+              # test-bundled-gems-fetch requires git
+              unset APT_INSTALL_GIT
+              ;;
+            test-bundler*)
+              # avoid Bundler::Source::Git::GitNotInstalledError
+              unset APT_INSTALL_GIT
+              ;;
+            *)
+              ;;
+          esac
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev bison- autoconf- $APT_INSTALL_GIT
+        if: inputs.apt-mode == 'git-only'
+      - name: Install libraries (apt-mode=ruby-and-git)
+        run: |
+          set -x
+          sudo apt-get update -q || :
+          # postfix `-` means `uninstall`
+          APT_INSTALL_RUBY=ruby-
+          APT_INSTALL_GIT=git-
+          case "${{ matrix.test_task }}" in
+            test-bundled-gems)
+              # test-bundled-gems requires executable host ruby
+              APT_INSTALL_RUBY=ruby
+              # test-bundled-gems-fetch requires git
+              unset APT_INSTALL_GIT
+              ;;
+            test-bundler*)
+              # avoid Bundler::Source::Git::GitNotInstalledError
+              unset APT_INSTALL_GIT
+              ;;
+            *)
+              ;;
+          esac
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev bison- autoconf- $APT_INSTALL_RUBY $APT_INSTALL_GIT
+        if: inputs.apt-mode == 'ruby-and-git'
+      - uses: ruby/setup-ruby@c4e5b1316158f92e3d49443a9d58b31d25ac0f8f # v1.306.0
+        with:
+          ruby-version: 3.2
+        # test-bundled-gems requires executable host ruby
+        if: inputs.setup-host-ruby && matrix.test_task == 'test-bundled-gems'
+      - name: Fixed world writable dirs
+        run: |
+          mkdir -p $HOME/.local
+          mkdir -p $HOME/.cache/gem/specs
+          mkdir -p $HOME/.bundle/cache
+          chmod a-w $HOME/.bundle
+          # chmod a-w $HOME
+          # allow to write $HOME and check stats of HOME around tests (see below)
+          chmod -v a-w $HOME/.config
+          sudo chmod -R a-w /usr/share
+          sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v a-w $d; done' || :
+      - name: Fixed world writable dirs (extra)
+        run: |
+          mkdir -p $HOME/.local/share
+          mkdir -p $HOME/.ssh
+        if: inputs.fixed-dirs-extra
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - name: configure
+        run: cd snapshot-*/ && ./configure
+      - name: make
+        run: cd snapshot-*/ && make $JOBS
+      - name: Save stats of HOME
+        run: |
+          set -euxo pipefail
+          cd snapshot-*/
+          cat >test.rb <<'EOF'
+          require 'pathname'
+          require 'digest'
+          out = []
+          [
+            Dir.home,
+          ].each do |dir|
+            Pathname(dir).each_child do |pn|
+              st = pn.stat
+              if st.file?
+                content = Digest::SHA1.hexdigest(pn.read)
+              elsif st.directory? && st.nlink <= 10
+                content = pn.children.map(&:basename).map(&:to_s).sort
+              end
+              out << [pn.to_s, "%o"%st.mode, st.nlink, st.uid, st.gid, st.size, content].to_s
+            rescue
+              out << [pn.to_s, $!.inspect].to_s
+            end
+          end
+          File.open("/tmp/stat-before-tests.txt", "w") do |io|
+            io.puts out.sort
+          end
+          EOF
+          make runruby
+          rm -f test.rb
+      - name: Tests
+        run: cd snapshot-*/ && make $JOBS -s ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: "-q --tty=no"
+      # not sure why ~/.gnupg is remained
+      # see tool/test/test_sync_default_gems.rb
+      - name: Forcibly remove test directory
+        run: rm -rf $HOME/.gnupg
+        if: inputs.remove-gnupg
+      - name: Diff stats of HOME
+        run: |
+          set -euxo pipefail
+          cd snapshot-*/
+          cat >test.rb <<'EOF'
+          require 'pathname'
+          require 'digest'
+          out = []
+          [
+            Dir.home,
+          ].each do |dir|
+            Pathname(dir).each_child do |pn|
+              st = pn.stat
+              if st.file?
+                content = Digest::SHA1.hexdigest(pn.read)
+              elsif st.directory? && st.nlink <= 10
+                content = pn.children.map(&:basename).map(&:to_s).sort
+              end
+              out << [pn.to_s, "%o"%st.mode, st.nlink, st.uid, st.gid, st.size, content].to_s
+            rescue
+              out << [pn.to_s, $!.inspect].to_s
+            end
+          end
+          File.open("/tmp/stat-after-tests.txt", "w") do |io|
+            io.puts out.sort
+          end
+          EOF
+          make runruby
+          rm -f test.rb
+          diff -u /tmp/stat-before-tests.txt /tmp/stat-after-tests.txt
+      # leaked-globals since 2.7
+      - name: Leaked Globals
+        run: cd snapshot-*/ && make -s leaked-globals
+        if: matrix.test_task == 'check'
+      - name: make install without root privilege
+        run: cd snapshot-*/ && make $JOBS install DESTDIR="/tmp/destdir"
+        if: matrix.test_task == 'check'
+      - name: make install
+        run: cd snapshot-*/ && sudo make $JOBS install
+        if: matrix.test_task == 'check'
+      - name: ruby -v
+        env:
+          RUBY_BIN: ${{ inputs.ruby-bin }}
+        run: '"$RUBY_BIN" -v'
+        if: matrix.test_task == 'check'
+      - name: Show .local
+        run: find $HOME/.local -ls
+      - uses: ruby/action-slack@54175162371f1f7c8eb94d7c8644ee2479fcd375 # v3.2.2
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ matrix.os }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|${{ github.workflow }}>",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+        if: failure() && github.event_name == 'schedule'
+      - name: Get ruby/ruby sha
+        id: ruby_sha
+        run: cd snapshot-*/ && ./ruby -e 'puts "sha=#{RUBY_REVISION}"' >> $GITHUB_OUTPUT
+        if: failure() && inputs.notify-ruby-sha && github.event_name == 'schedule'
+      - uses: ruby/action-slack@54175162371f1f7c8eb94d7c8644ee2479fcd375 # v3.2.2
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "snapshot: ${{ matrix.os }} / ${{ matrix.test_task }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ steps.ruby_sha.outputs.sha }}",
+              "branch": "${{ inputs.branch-label }}"
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }}
+        if: failure() && inputs.notify-ruby-sha && github.event_name == 'schedule'
diff --git a/.github/workflows/tarball-windows.yml b/.github/workflows/tarball-windows.yml
new file mode 100644
index 00000000000000..9c7940e1729477
--- /dev/null
+++ b/.github/workflows/tarball-windows.yml
@@ -0,0 +1,174 @@
+name: tarball-windows (reusable)
+
+on:
+  workflow_call:
+    inputs:
+      archname:
+        description: 'archname (e.g. snapshot-master)'
+        required: true
+        type: string
+      patch-url:
+        description: 'Patch URL forwarded from workflow_dispatch'
+        required: false
+        type: string
+        default: ''
+      mode:
+        description: '"modern" (vssetup + 2022/2025-vs2026) or "legacy" (vs2022 + vcvars 14.2 + test-all/test-spec split)'
+        required: false
+        type: string
+        default: 'modern'
+
+jobs:
+  windows:
+    strategy:
+      matrix:
+        include: ${{ fromJSON(inputs.mode == 'legacy'
+          && '[{"os":"2022","vs":2022,"vcvars":"10.0.22621.0 -vcvars_ver=14.2","test_task":"check"}]'
+          || '[{"os":"2022","test_task":"check"},{"os":"2025-vs2026","test_task":"check"}]') }}
+      fail-fast: false
+    runs-on: windows-${{ matrix.os }}
+    defaults:
+      run:
+        shell: cmd
+        working-directory: build
+    name: Windows ${{ matrix.os }} (${{ matrix.test_task }})
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+      PATCH: C:\msys64\usr\bin\patch.exe
+      OS_VER: windows-${{ matrix.os }}
+      # see https://github.com/ruby/ruby/commit/9ff4399decef0036897d3cfb9ac2c710dea913ca
+      OPENSSL_MODULES: C:\vcpkg\installed\x64-windows\bin
+    steps:
+      - run: md build
+        working-directory:
+
+      - uses: ruby/setup-ruby@c4e5b1316158f92e3d49443a9d58b31d25ac0f8f # v1.306.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+          windows-toolchain: none
+
+      - uses: msys2/setup-msys2@e9898307ac31d1a803454791be09ab9973336e1c # v2.31.1
+        id: setup-msys2
+        with:
+          update: true
+          install: >-
+            patch
+      - name: patch path
+        shell: msys2 {0}
+        run: echo PATCH=$(cygpath -wa $(command -v patch)) >> $GITHUB_ENV
+        if: ${{ steps.setup-msys2.outcome == 'success' }}
+      - uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: C:\vcpkg\installed
+          key: ${{ runner.os }}-vcpkg-installed-${{ env.OS_VER }}-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-vcpkg-installed-${{ env.OS_VER }}-
+            ${{ runner.os }}-vcpkg-installed-
+      - name: Install libraries with vcpkg
+        run: |
+          vcpkg --triplet x64-windows install libffi libyaml openssl readline zlib
+
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: 7z x pkg/*.zip
+        working-directory:
+      - name: Apply patch
+        run: |
+          set -x
+          curl -sSL "${RUBY_PATCH_URL}" -o ruby.patch
+          cd "$ARCHNAME"
+          git apply ../ruby.patch
+        shell: bash
+        env:
+          RUBY_PATCH_URL: ${{ inputs.patch-url }}
+          ARCHNAME: ${{ inputs.archname }}
+        if: inputs.patch-url != ''
+        working-directory:
+
+      - uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: snapshot-*/.downloaded-cache
+          key: downloaded-cache
+
+      - name: setup env (modern)
+        # %TEMP% is inconsistent with %TMP% and test-all expects they are consistent.
+        # https://github.com/actions/virtual-environments/issues/712#issuecomment-613004302
+        env:
+          ARCHNAME: ${{ inputs.archname }}
+        run: |
+          set > old.env
+          call ..\%ARCHNAME%\win32\vssetup.cmd
+          set TMP=%USERPROFILE%\AppData\Local\Temp
+          set TEMP=%USERPROFILE%\AppData\Local\Temp
+          set /a TEST_JOBS=(15 * %NUMBER_OF_PROCESSORS% / 10) > nul
+          set > new.env
+        if: inputs.mode == 'modern'
+      - name: setup env (legacy)
+        run: |
+          if not "%VCVARS%" == "" goto :vcset
+            set VCVARS="C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+            if not exist %VCVARS% set VCVARS="C:\Program Files\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+          :vcset
+          set > old.env
+          call %VCVARS% ${{ matrix.vcvars }}
+          set TMP=%USERPROFILE%\AppData\Local\Temp
+          set TEMP=%USERPROFILE%\AppData\Local\Temp
+          set /a TEST_JOBS=(15 * %NUMBER_OF_PROCESSORS% / 10) > nul
+          set > new.env
+        if: inputs.mode == 'legacy'
+
+      - name: update env
+        shell: pwsh
+        run: |
+          $old = (Get-Content old.env); $new = (Get-Content new.env)
+          del *.env
+          Compare-Object $old $new |
+            Where-Object { $_.SideIndicator -eq '=>' } |
+            Select-Object -ExpandProperty InputObject |
+            Add-Content -Path $env:GITHUB_ENV
+      - name: link libraries
+        run: |
+          for %%I in (C:\vcpkg\installed\x64-windows\bin\*.dll) do (
+            if not %%~nI == readline mklink %%~nxI %%I
+          )
+      - name: Configure
+        env:
+          ARCHNAME: ${{ inputs.archname }}
+        run: >-
+          ../%ARCHNAME%/win32/configure.bat --disable-install-doc
+          --with-opt-dir=C:/vcpkg/installed/x64-windows
+      - run: nmake incs
+      - run: nmake extract-extlibs
+      - run: nmake
+        env:
+          YACC: win_bison
+
+      - name: ruby -v
+        run: |
+          .\ruby -v
+
+      - run: nmake test
+        timeout-minutes: 5
+
+      - run: nmake ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: -j${{env.TEST_JOBS}}
+        timeout-minutes: 70
+        continue-on-error: ${{ matrix.continue-on-error || false }}
+
+      - uses: ruby/action-slack@54175162371f1f7c8eb94d7c8644ee2479fcd375 # v3.2.2
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ env.OS_VER }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|${{ github.workflow }}>",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+        if: failure() && github.event_name == 'schedule'
diff --git a/box.c b/box.c
index b55e8bb137a576..0ca7838be96045 100644
--- a/box.c
+++ b/box.c
@@ -860,8 +860,7 @@ rb_box_load(int argc, VALUE *argv, VALUE box)
 
     rb_vm_frame_flag_set_box_require(GET_EC());
 
-    VALUE args = rb_ary_new_from_args(2, fname, wrap);
-    return rb_load_entrypoint(args);
+    return rb_load_entrypoint(fname, wrap);
 }
 
 static VALUE
diff --git a/coroutine/ppc64le/Context.S b/coroutine/ppc64le/Context.S
index f7bcae2c3af400..819264c245ce9b 100644
--- a/coroutine/ppc64le/Context.S
+++ b/coroutine/ppc64le/Context.S
@@ -1,11 +1,18 @@
 #define TOKEN_PASTE(x,y) x##y
 
+.abiversion 2
 .text
 .align 2
 
 .globl PREFIXED_SYMBOL(coroutine_transfer)
 .type   PREFIXED_SYMBOL(coroutine_transfer), @function
 PREFIXED_SYMBOL(coroutine_transfer):
+	# Global entry: set up TOC pointer (r2) from r12.
+	# Required by ELFv2 ABI when this function is reached via the PLT.
+	addis 2, 12, .TOC. - PREFIXED_SYMBOL(coroutine_transfer)@ha
+	addi  2, 2,  .TOC. - PREFIXED_SYMBOL(coroutine_transfer)@l
+	.localentry PREFIXED_SYMBOL(coroutine_transfer), .-PREFIXED_SYMBOL(coroutine_transfer)
+
 	# Make space on the stack for caller registers
 	addi 1,1,-160
 
diff --git a/internal/load.h b/internal/load.h
index fb880a43ba42e0..6cffe0ce64bcde 100644
--- a/internal/load.h
+++ b/internal/load.h
@@ -12,7 +12,7 @@
 
 /* load.c */
 VALUE rb_get_expanded_load_path(void);
-VALUE rb_load_entrypoint(VALUE args);
+VALUE rb_load_entrypoint(VALUE fname, VALUE wrap);
 VALUE rb_require_relative_entrypoint(VALUE fname);
 int rb_require_internal(VALUE fname);
 NORETURN(void rb_load_fail(VALUE, const char*));
diff --git a/load.c b/load.c
index f7bdf07641a84e..1ee66e2bfcd3e9 100644
--- a/load.c
+++ b/load.c
@@ -875,8 +875,8 @@ rb_load_protect(VALUE fname, int wrap, int *pstate)
     if (state != TAG_NONE) *pstate = state;
 }
 
-static VALUE
-load_entrypoint_internal(VALUE fname, VALUE wrap)
+VALUE
+rb_load_entrypoint(VALUE fname, VALUE wrap)
 {
     VALUE path, orig_fname;
 
@@ -897,18 +897,6 @@ load_entrypoint_internal(VALUE fname, VALUE wrap)
     return Qtrue;
 }
 
-VALUE
-rb_load_entrypoint(VALUE args)
-{
-    VALUE fname, wrap;
-    if (RARRAY_LEN(args) != 2) {
-        rb_bug("invalid arguments: %ld", RARRAY_LEN(args));
-    }
-    fname = rb_ary_entry(args, 0);
-    wrap = rb_ary_entry(args, 1);
-    return load_entrypoint_internal(fname, wrap);
-}
-
 /*
  *  call-seq:
  *     load(filename, wrap=false)   -> true
@@ -944,7 +932,7 @@ rb_f_load(int argc, VALUE *argv, VALUE _)
 {
     VALUE fname, wrap;
     rb_scan_args(argc, argv, "11", &fname, &wrap);
-    return load_entrypoint_internal(fname, wrap);
+    return rb_load_entrypoint(fname, wrap);
 }
 
 static char *
diff --git a/test/pathname/test_pathname.rb b/test/pathname/test_pathname.rb
index c5b19c8b18fbd3..6354e6a9b5dd3c 100644
--- a/test/pathname/test_pathname.rb
+++ b/test/pathname/test_pathname.rb
@@ -175,19 +175,19 @@ def del_trailing_separator(path)
 
   if DOSISH_UNC
     defassert(:del_trailing_separator, "//", "//")
-    defassert(:del_trailing_separator, "//a", "//a")
-    defassert(:del_trailing_separator, "//a", "//a/")
-    defassert(:del_trailing_separator, "//a", "//a//")
-    defassert(:del_trailing_separator, "//a/b", "//a/b")
-    defassert(:del_trailing_separator, "//a/b", "//a/b/")
-    defassert(:del_trailing_separator, "//a/b", "//a/b//")
-    defassert(:del_trailing_separator, "//a/b/c", "//a/b/c")
-    defassert(:del_trailing_separator, "//a/b/c", "//a/b/c/")
-    defassert(:del_trailing_separator, "//a/b/c", "//a/b/c//")
   else
     defassert(:del_trailing_separator, "/", "///")
-    defassert(:del_trailing_separator, "///a", "///a/")
   end
+  defassert(:del_trailing_separator, "//a", "//a")
+  defassert(:del_trailing_separator, "//a", "//a/")
+  defassert(:del_trailing_separator, "//a", "//a//")
+  defassert(:del_trailing_separator, "//a/b", "//a/b")
+  defassert(:del_trailing_separator, "//a/b", "//a/b/")
+  defassert(:del_trailing_separator, "//a/b", "//a/b//")
+  defassert(:del_trailing_separator, "//a/b/c", "//a/b/c")
+  defassert(:del_trailing_separator, "//a/b/c", "//a/b/c/")
+  defassert(:del_trailing_separator, "//a/b/c", "//a/b/c//")
+  defassert(:del_trailing_separator, "///a", "///a/")
 
   if DOSISH
     defassert(:del_trailing_separator, "a", "a\\")
@@ -260,13 +260,12 @@ def test_join
     assert_equal(Pathname("/foo/var"), r)
   end
 
-  def test_absolute
-    assert_equal(true, Pathname("/").absolute?)
-    assert_equal(false, Pathname("a").absolute?)
-  end
-
   def relative?(path)
-    Pathname.new(path).relative?
+    path = Pathname.new(path)
+    relative = path.relative?
+    absolute = path.absolute?
+    assert_equal(!relative, absolute)
+    relative
   end
 
   defassert(:relative?, true, '')
@@ -281,7 +280,7 @@ def relative?(path)
   defassert(:relative?, !DOSISH_DRIVE_LETTER, 'A:/')
   defassert(:relative?, !DOSISH_DRIVE_LETTER, 'A:/a')
 
-  if File.dirname('//') == '//'
+  if DOSISH_UNC
     defassert(:relative?, false, '//')
     defassert(:relative?, false, '//a')
     defassert(:relative?, false, '//a/')
diff --git a/test/ruby/test_metaclass.rb b/test/ruby/test_metaclass.rb
index 8c1990a78cfb2c..6570fa5945b798 100644
--- a/test/ruby/test_metaclass.rb
+++ b/test/ruby/test_metaclass.rb
@@ -163,6 +163,6 @@ def metametaclass_method_b; end
     assert_nothing_raised{ metametaclass_of_bar.metaclass_method_c }
     assert_nothing_raised{ metametaclass_of_bar.metametaclass_method_o }
     assert_nothing_raised{ metametaclass_of_bar.metametaclass_method_f }
-    assert_raise(NoMethodError){ metametaclass_of_bar.metaclass_method_b }
+    assert_raise(NoMethodError){ metametaclass_of_bar.metametaclass_method_b }
   end
 end