diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index b00f6d0452c242..c783f6ac6b2e9f 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -33,10 +33,9 @@ jobs:
             test_task: check
           - os: 2025-vs2026
             test_task: test-bundled-gems
-          # TODO: Debug why Windows 11 ARM is failing to build on CI
-          # - os: 11-arm
-          #   test_task: 'btest test-basic test-tool' # check and test-spec are broken yet.
-          #   target: arm64
+          - os: 11-arm
+            test_task: 'btest test-basic test-tool' # check and test-spec are broken yet.
+            target: arm64
       fail-fast: false
 
     runs-on: windows-${{ matrix.os }}
@@ -81,10 +80,11 @@ jobs:
 
       - name: Install tools with scoop
         run: |
+          if ((vcpkg.exe help install) -match "manifest") { exit }
           Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
           iwr -useb get.scoop.sh | iex
           Join-Path (Resolve-Path ~).Path "scoop\shims" >> $Env:GITHUB_PATH
-          scoop install vcpkg uutils-coreutils
+          scoop install vcpkg
         shell: pwsh
 
       - name: Restore vcpkg artifact
@@ -96,7 +96,7 @@ jobs:
 
       - name: Install libraries with vcpkg
         run: |
-          vcpkg install --vcpkg-root=%USERPROFILE%\scoop\apps\vcpkg\current
+          vcpkg install
         working-directory: src
         if: ${{ ! steps.restore-vcpkg.outputs.cache-hit }}
 
@@ -112,11 +112,7 @@ jobs:
         # %TEMP% is inconsistent with %TMP% and test-all expects they are consistent.
         # https://github.com/actions/virtual-environments/issues/712#issuecomment-613004302
         run: |
-          ::- Using sort.exe located in the same directory as comm.exe
-          ::- should probably work just fine.
-          for %%I in (comm.exe) do set "sort=%%~dp$PATH:I\sort.exe"
-
-          set | "%sort%" > old.env
+          set > old.env
           call ..\src\win32\vssetup.cmd ^
             -arch=${{ matrix.target || 'amd64' }} ^
             ${{ matrix.vcvars && '-vcvars_ver=' || '' }}${{ matrix.vcvars }}
@@ -126,9 +122,17 @@ jobs:
           set MAKEFLAGS=l
           set /a TEST_JOBS=(15 * %NUMBER_OF_PROCESSORS% / 10) > nul
           set RUBY_OPT_DIR=%GITHUB_WORKSPACE:\=/%/src/vcpkg_installed/%VCPKG_DEFAULT_TRIPLET%
-          set | "%sort%" > new.env
-          comm -13 old.env new.env >> %GITHUB_ENV%
+          set > new.env
+
+      - 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: baseruby version
         run: ruby -v
diff --git a/tool/format-release b/tool/format-release
index 8bb61542433fb2..d02154df1f967f 100755
--- a/tool/format-release
+++ b/tool/format-release
@@ -51,7 +51,7 @@ eom
   #   SHA1:   21f62c369661a2ab1b521fd2fa8191a4273e12a1
   #   SHA256: 97cea8aa63dfa250ba6902b658a7aa066daf817b22f82b7ee28f44aec7c2e394
   #   SHA512: 1e2042324821bb4e110af7067f52891606dcfc71e640c194ab1c117f0b941550e0b3ac36ad3511214ac80c536b9e5cfaf8789eec74cf56971a832ea8fc4e6d94
-  def self.parse(wwwdir, version, rubydir)
+  def self.parse(wwwdir, version, rubydir, source_ref_or_sha = nil)
     unless /\A(\d+)\.(\d+)\.(\d+)(?:-(?:preview|rc)\d+)?\z/ =~ version
       raise "unexpected version string '#{version}'"
     end
@@ -75,9 +75,12 @@ eom
 
     if teeny == 0
       # show diff shortstat
-      tag = RubyVersion.tag(version)
+      tag = source_ref_or_sha || RubyVersion.tag(version)
       prev_tag = RubyVersion.tag(RubyVersion.previous(version))
-      stat = `git -C #{rubydir} diff -l0 --shortstat #{prev_tag}..#{tag}`
+      stat = IO.popen(["git", "-C", rubydir, "diff", "-l0", "--shortstat", "#{prev_tag}..#{tag}"], &:read)
+      unless $?.success?
+        raise "failed to diff #{prev_tag}..#{tag}"
+      end
       files_changed, insertions, deletions = stat.scan(/\d+/)
     end
 
@@ -235,11 +238,12 @@ def main
   wwwdir = ARGV.shift
   version = ARGV.shift
   rubydir = ARGV.shift
+  source_ref_or_sha = ARGV.shift
   unless rubydir
-    STDERR.puts "usage: format-release <dir-of-w.r-l.o> <version> <ruby-dir>"
+    STDERR.puts "usage: format-release <dir-of-w.r-l.o> <version> <ruby-dir> [source-ref-or-sha]"
     exit
   end
-  Tarball.parse(wwwdir, version, rubydir)
+  Tarball.parse(wwwdir, version, rubydir, source_ref_or_sha)
 end
 
 main