From 6a4fa1b6a81c07bb00df31db279dfe0f19306c8c Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 10 Aug 2026 16:44:08 +0000
Subject: [PATCH 1/7] Speed up Windows CI by scoping targets and adding
 cache/profile

Co-authored-by: tameware <4573152+tameware@users.noreply.github.com>
---
 .github/workflows/ci_windows.yml        | 57 ++++++++++++++++++++-----
 python/tests/ci_windows_cppopts_test.py | 32 ++++++++++++--
 2 files changed, 75 insertions(+), 14 deletions(-)

diff --git a/.github/workflows/ci_windows.yml b/.github/workflows/ci_windows.yml
index 94e97789..86d08108 100644
--- a/.github/workflows/ci_windows.yml
+++ b/.github/workflows/ci_windows.yml
@@ -9,6 +9,14 @@ jobs:
   build_and_test:
     runs-on: windows-latest
     timeout-minutes: 20
+    env:
+      BAZEL_DISK_CACHE: ${{ github.workspace }}\.bazel-cache\disk
+      BAZEL_PROFILE_JSON: ${{ github.workspace }}\windows-fastbuild-profile.json.gz
+      BAZEL_PROFILE_TXT: ${{ github.workspace }}\windows-fastbuild-profile.txt
+      WINDOWS_FASTBUILD_TARGETS: >-
+        //library/... //examples/... //python/... //jni/...
+      WINDOWS_OPT_TARGETS: >-
+        //library/src:dds //examples:analyse_play_pbn
     steps:
       # Checkout the repository
       - name: Checkout repository
@@ -18,13 +26,23 @@ jobs:
       - name: Setup Bazelisk
         uses: ./.github/actions/setup-bazelisk
 
-      # Warm external deps (emsdk, LLVM, …); retry transient network fetch failures
+      # Reuse compiled/action cache artifacts across workflow runs
+      - name: Restore Bazel disk cache
+        uses: actions/cache@v4
+        with:
+          path: ${{ github.workspace }}\.bazel-cache\disk
+          key: windows-bazel-disk-cache-${{ runner.os }}-${{ hashFiles('.bazelversion', '.bazelrc', 'MODULE.bazel', 'BUILD.bazel', 'CPPVARIABLES.bzl') }}
+          restore-keys: |
+            windows-bazel-disk-cache-${{ runner.os }}-
+
+      # Warm external deps for the same scope tested on Windows
       - name: Prefetch external repos
         shell: pwsh
         run: |
+          $fastbuild_targets = $env:WINDOWS_FASTBUILD_TARGETS -split ' '
           $max = 3
           for ($i = 1; $i -le $max; $i++) {
-            bazelisk fetch //...
+            bazelisk fetch --disk_cache="$env:BAZEL_DISK_CACHE" --verbose_failures $fastbuild_targets
             if ($LASTEXITCODE -eq 0) { exit 0 }
             if ($i -lt $max) {
               Write-Host "Fetch failed (attempt $i/$max). Retrying in 20s..."
@@ -33,15 +51,21 @@ jobs:
           }
           exit 1
 
-      # Build all targets (retry: fetch flakes can still surface on first analysis).
-      # --config=opt: DDS_CPPOPTS no longer forces /O2 (that fought Bazel's /Od and
-      # triggered MSVC D9025); opt mode is how Windows keeps release-level codegen.
-      - name: Bazel build (retry on transient fetch failure)
+      # Run Windows-native coverage in fastbuild (test-centric flow)
+      - name: Run Windows test targets
+        shell: pwsh
+        run: |
+          $fastbuild_targets = $env:WINDOWS_FASTBUILD_TARGETS -split ' '
+          bazelisk test --disk_cache="$env:BAZEL_DISK_CACHE" --profile="$env:BAZEL_PROFILE_JSON" --verbose_failures $fastbuild_targets
+
+      # Keep a narrow release-level check on Windows with --config=opt
+      - name: Build Windows opt smoke targets (retry on transient fetch failure)
         shell: pwsh
         run: |
+          $opt_targets = $env:WINDOWS_OPT_TARGETS -split ' '
           $max = 3
           for ($i = 1; $i -le $max; $i++) {
-            bazelisk build --config=opt --verbose_failures //...
+            bazelisk build --config=opt --disk_cache="$env:BAZEL_DISK_CACHE" --verbose_failures $opt_targets
             if ($LASTEXITCODE -eq 0) { exit 0 }
             if ($i -lt $max) {
               Write-Host "Build failed (attempt $i/$max). Retrying in 20s..."
@@ -52,9 +76,10 @@ jobs:
           }
           exit 1
 
-      # Run all tests (including Python) — no retry so real test failures surface quickly
-      - name: Run all tests
-        run: bazelisk test --config=opt --verbose_failures //...
+      # Summarize profile hotspots for follow-up CI tuning
+      - name: Analyze Bazel profile
+        shell: pwsh
+        run: bazelisk analyze-profile "$env:BAZEL_PROFILE_JSON" | Out-File -FilePath "$env:BAZEL_PROFILE_TXT" -Encoding utf8
 
       # Upload test logs
       - name: Upload test logs - Windows
@@ -65,3 +90,15 @@ jobs:
           path: bazel-testlogs/
           if-no-files-found: ignore
           retention-days: 30
+
+      # Upload profile artifacts
+      - name: Upload Bazel profile - Windows
+        if: always()
+        uses: actions/upload-artifact@v6
+        with:
+          name: bazel-profile-windows
+          path: |
+            ${{ github.workspace }}\windows-fastbuild-profile.json.gz
+            ${{ github.workspace }}\windows-fastbuild-profile.txt
+          if-no-files-found: ignore
+          retention-days: 30
diff --git a/python/tests/ci_windows_cppopts_test.py b/python/tests/ci_windows_cppopts_test.py
index c31ea411..3fe1b5d9 100644
--- a/python/tests/ci_windows_cppopts_test.py
+++ b/python/tests/ci_windows_cppopts_test.py
@@ -67,6 +67,10 @@ def _bazelisk_invocation_has_config_opt(text: str, subcommand: str) -> bool:
     return False
 
 
+def _workflow_lines_with(text: str, needle: str) -> list[str]:
+    return [line for line in text.splitlines() if needle in line]
+
+
 class TestWindowsMsvcCppoptsAvoidD9025(unittest.TestCase):
     def test_windows_cppopts_do_not_override_bazel_optimization(self) -> None:
         """Bazel already sets /Od (fastbuild/dbg) or /O2 (opt); re-stating any
@@ -360,17 +364,37 @@ def test_matches_when_config_opt_precedes_trailing_comment(self) -> None:
 
 class TestWindowsCiUsesOpt(unittest.TestCase):
     def test_windows_ci_passes_config_opt(self) -> None:
-        """Without /O2 in DDS_CPPOPTS, CI must opt in via --config=opt."""
+        """Windows CI keeps opt only for a focused release validation step."""
         text = (
             _repo_root() / ".github" / "workflows" / "ci_windows.yml"
         ).read_text(encoding="utf-8")
+        self.assertFalse(
+            _bazelisk_invocation_has_config_opt(text, "test"),
+            "expected broad Windows test coverage to run in fastbuild",
+        )
         self.assertTrue(
             _bazelisk_invocation_has_config_opt(text, "build"),
-            "expected Windows CI build to use --config=opt",
+            "expected a focused Windows build step to keep --config=opt",
         )
+
+    def test_windows_ci_limits_scope_and_collects_profile(self) -> None:
+        text = (
+            _repo_root() / ".github" / "workflows" / "ci_windows.yml"
+        ).read_text(encoding="utf-8")
+        self.assertIn("WINDOWS_FASTBUILD_TARGETS", text)
+        self.assertNotIn("bazelisk fetch //...", text)
+        self.assertNotIn("bazelisk test --verbose_failures //...", text)
+        self.assertNotIn("bazelisk build --config=opt --verbose_failures //...", text)
+        self.assertIn("bazelisk analyze-profile", text)
+        self.assertRegex(
+            text,
+            r"actions/cache@v4",
+            "expected Windows workflow to enable cross-run Bazel caching",
+        )
+        test_lines = _workflow_lines_with(text, "bazelisk test")
         self.assertTrue(
-            _bazelisk_invocation_has_config_opt(text, "test"),
-            "expected Windows CI test to use --config=opt",
+            any("--profile=" in line for line in test_lines),
+            "expected Windows test command to emit a Bazel profile",
         )
 
 

From dd111446e6da467cd6c50e58bafbacd96ad4c10c Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 10 Aug 2026 21:37:30 +0000
Subject: [PATCH 2/7] Cache Bazelisk downloads in Windows CI

Co-authored-by: tameware <4573152+tameware@users.noreply.github.com>
---
 .github/workflows/ci_windows.yml | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/.github/workflows/ci_windows.yml b/.github/workflows/ci_windows.yml
index 86d08108..12b27204 100644
--- a/.github/workflows/ci_windows.yml
+++ b/.github/workflows/ci_windows.yml
@@ -10,6 +10,7 @@ jobs:
     runs-on: windows-latest
     timeout-minutes: 20
     env:
+      BAZELISK_HOME: ${{ github.workspace }}\.bazel-cache\bazelisk
       BAZEL_DISK_CACHE: ${{ github.workspace }}\.bazel-cache\disk
       BAZEL_PROFILE_JSON: ${{ github.workspace }}\windows-fastbuild-profile.json.gz
       BAZEL_PROFILE_TXT: ${{ github.workspace }}\windows-fastbuild-profile.txt
@@ -22,6 +23,15 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v6
 
+      # Reuse downloaded Bazel binaries across workflow runs
+      - name: Restore Bazelisk cache
+        uses: actions/cache@v4
+        with:
+          path: ${{ env.BAZELISK_HOME }}
+          key: windows-bazelisk-cache-${{ runner.os }}-${{ hashFiles('.bazelversion') }}
+          restore-keys: |
+            windows-bazelisk-cache-${{ runner.os }}-
+
       # Install Bazelisk (recommended Bazel launcher)
       - name: Setup Bazelisk
         uses: ./.github/actions/setup-bazelisk

From 541f8a76724233bf3615f0e9b3e28668d231e5ad Mon Sep 17 00:00:00 2001
From: Adam Wildavsky <adam@tameware.com>
Date: Mon, 10 Aug 2026 22:52:15 +0100
Subject: [PATCH 3/7] Apply suggestions from code review

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 .github/workflows/ci_windows.yml | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/ci_windows.yml b/.github/workflows/ci_windows.yml
index 12b27204..d09c1173 100644
--- a/.github/workflows/ci_windows.yml
+++ b/.github/workflows/ci_windows.yml
@@ -41,7 +41,7 @@ jobs:
         uses: actions/cache@v4
         with:
           path: ${{ github.workspace }}\.bazel-cache\disk
-          key: windows-bazel-disk-cache-${{ runner.os }}-${{ hashFiles('.bazelversion', '.bazelrc', 'MODULE.bazel', 'BUILD.bazel', 'CPPVARIABLES.bzl') }}
+          key: windows-bazel-disk-cache-${{ runner.os }}-${{ hashFiles('.bazelversion', '.bazelrc', 'MODULE.bazel', 'MODULE.bazel.lock', 'BUILD.bazel', 'CPPVARIABLES.bzl') }}
           restore-keys: |
             windows-bazel-disk-cache-${{ runner.os }}-
 
@@ -88,8 +88,14 @@ jobs:
 
       # Summarize profile hotspots for follow-up CI tuning
       - name: Analyze Bazel profile
+        if: always()
         shell: pwsh
-        run: bazelisk analyze-profile "$env:BAZEL_PROFILE_JSON" | Out-File -FilePath "$env:BAZEL_PROFILE_TXT" -Encoding utf8
+        run: |
+          if (Test-Path "$env:BAZEL_PROFILE_JSON") {
+            bazelisk analyze-profile "$env:BAZEL_PROFILE_JSON" | Out-File -FilePath "$env:BAZEL_PROFILE_TXT" -Encoding utf8
+          } else {
+            Write-Host "No Bazel profile found at $env:BAZEL_PROFILE_JSON; skipping analyze-profile."
+          }
 
       # Upload test logs
       - name: Upload test logs - Windows

From a7606633f41475fd27533942308f0053a4ae9bd6 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 10 Aug 2026 21:55:20 +0000
Subject: [PATCH 4/7] Fix Windows CI: use PowerShell array splatting (@arr) to
 pass Bazel targets as separate args

Previously, $arr passed to a native command in PowerShell joined array
elements into a single space-separated string, so Bazel received the
full target list as one invalid package name. Switching to @arr splatting
passes each element as a distinct argument across all PowerShell versions.

Also use -split '\s+' with a non-empty filter to tolerate any whitespace
variation in the env var value.

Co-authored-by: tameware <4573152+tameware@users.noreply.github.com>
---
 .github/workflows/ci_windows.yml | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/.github/workflows/ci_windows.yml b/.github/workflows/ci_windows.yml
index d09c1173..74b6c6e9 100644
--- a/.github/workflows/ci_windows.yml
+++ b/.github/workflows/ci_windows.yml
@@ -49,10 +49,10 @@ jobs:
       - name: Prefetch external repos
         shell: pwsh
         run: |
-          $fastbuild_targets = $env:WINDOWS_FASTBUILD_TARGETS -split ' '
+          [string[]]$fastbuild_targets = $env:WINDOWS_FASTBUILD_TARGETS -split '\s+' | Where-Object { $_ -ne '' }
           $max = 3
           for ($i = 1; $i -le $max; $i++) {
-            bazelisk fetch --disk_cache="$env:BAZEL_DISK_CACHE" --verbose_failures $fastbuild_targets
+            bazelisk fetch --disk_cache="$env:BAZEL_DISK_CACHE" --verbose_failures @fastbuild_targets
             if ($LASTEXITCODE -eq 0) { exit 0 }
             if ($i -lt $max) {
               Write-Host "Fetch failed (attempt $i/$max). Retrying in 20s..."
@@ -65,17 +65,17 @@ jobs:
       - name: Run Windows test targets
         shell: pwsh
         run: |
-          $fastbuild_targets = $env:WINDOWS_FASTBUILD_TARGETS -split ' '
-          bazelisk test --disk_cache="$env:BAZEL_DISK_CACHE" --profile="$env:BAZEL_PROFILE_JSON" --verbose_failures $fastbuild_targets
+          [string[]]$fastbuild_targets = $env:WINDOWS_FASTBUILD_TARGETS -split '\s+' | Where-Object { $_ -ne '' }
+          bazelisk test --disk_cache="$env:BAZEL_DISK_CACHE" --profile="$env:BAZEL_PROFILE_JSON" --verbose_failures @fastbuild_targets
 
       # Keep a narrow release-level check on Windows with --config=opt
       - name: Build Windows opt smoke targets (retry on transient fetch failure)
         shell: pwsh
         run: |
-          $opt_targets = $env:WINDOWS_OPT_TARGETS -split ' '
+          [string[]]$opt_targets = $env:WINDOWS_OPT_TARGETS -split '\s+' | Where-Object { $_ -ne '' }
           $max = 3
           for ($i = 1; $i -le $max; $i++) {
-            bazelisk build --config=opt --disk_cache="$env:BAZEL_DISK_CACHE" --verbose_failures $opt_targets
+            bazelisk build --config=opt --disk_cache="$env:BAZEL_DISK_CACHE" --verbose_failures @opt_targets
             if ($LASTEXITCODE -eq 0) { exit 0 }
             if ($i -lt $max) {
               Write-Host "Build failed (attempt $i/$max). Retrying in 20s..."

From 98d42034c1aba8b53693041e679a94e457c69641 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 10 Aug 2026 22:18:06 +0000
Subject: [PATCH 5/7] ci: remove analyze-profile step removed in Bazel 9

Co-authored-by: tameware <4573152+tameware@users.noreply.github.com>
---
 .github/workflows/ci_windows.yml | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/.github/workflows/ci_windows.yml b/.github/workflows/ci_windows.yml
index 74b6c6e9..89603f6f 100644
--- a/.github/workflows/ci_windows.yml
+++ b/.github/workflows/ci_windows.yml
@@ -13,7 +13,6 @@ jobs:
       BAZELISK_HOME: ${{ github.workspace }}\.bazel-cache\bazelisk
       BAZEL_DISK_CACHE: ${{ github.workspace }}\.bazel-cache\disk
       BAZEL_PROFILE_JSON: ${{ github.workspace }}\windows-fastbuild-profile.json.gz
-      BAZEL_PROFILE_TXT: ${{ github.workspace }}\windows-fastbuild-profile.txt
       WINDOWS_FASTBUILD_TARGETS: >-
         //library/... //examples/... //python/... //jni/...
       WINDOWS_OPT_TARGETS: >-
@@ -86,17 +85,6 @@ jobs:
           }
           exit 1
 
-      # Summarize profile hotspots for follow-up CI tuning
-      - name: Analyze Bazel profile
-        if: always()
-        shell: pwsh
-        run: |
-          if (Test-Path "$env:BAZEL_PROFILE_JSON") {
-            bazelisk analyze-profile "$env:BAZEL_PROFILE_JSON" | Out-File -FilePath "$env:BAZEL_PROFILE_TXT" -Encoding utf8
-          } else {
-            Write-Host "No Bazel profile found at $env:BAZEL_PROFILE_JSON; skipping analyze-profile."
-          }
-
       # Upload test logs
       - name: Upload test logs - Windows
         if: always()
@@ -115,6 +103,5 @@ jobs:
           name: bazel-profile-windows
           path: |
             ${{ github.workspace }}\windows-fastbuild-profile.json.gz
-            ${{ github.workspace }}\windows-fastbuild-profile.txt
           if-no-files-found: ignore
           retention-days: 30

From f0b6189bc85803852c0b4420c222ab82f9652b45 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 11 Aug 2026 06:15:01 +0000
Subject: [PATCH 6/7] ci: add bazelisk analyze-profile step to Windows workflow

Co-authored-by: tameware <4573152+tameware@users.noreply.github.com>
---
 .github/workflows/ci_windows.yml | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.github/workflows/ci_windows.yml b/.github/workflows/ci_windows.yml
index 89603f6f..2b5ccac8 100644
--- a/.github/workflows/ci_windows.yml
+++ b/.github/workflows/ci_windows.yml
@@ -85,6 +85,15 @@ jobs:
           }
           exit 1
 
+      # Summarise the profile captured during the test run
+      - name: Analyze Bazel profile
+        if: always()
+        shell: pwsh
+        run: |
+          if (Test-Path "$env:BAZEL_PROFILE_JSON") {
+            bazelisk analyze-profile "$env:BAZEL_PROFILE_JSON"
+          }
+
       # Upload test logs
       - name: Upload test logs - Windows
         if: always()

From 3ce36a2b2ad68f71646fe0df28e6fa4a74a5dd1e Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 11 Aug 2026 06:23:16 +0000
Subject: [PATCH 7/7] ci: remove bazelisk analyze-profile step and its test
 assertion

Co-authored-by: tameware <4573152+tameware@users.noreply.github.com>
---
 .github/workflows/ci_windows.yml        | 9 ---------
 python/tests/ci_windows_cppopts_test.py | 1 -
 2 files changed, 10 deletions(-)

diff --git a/.github/workflows/ci_windows.yml b/.github/workflows/ci_windows.yml
index 2b5ccac8..89603f6f 100644
--- a/.github/workflows/ci_windows.yml
+++ b/.github/workflows/ci_windows.yml
@@ -85,15 +85,6 @@ jobs:
           }
           exit 1
 
-      # Summarise the profile captured during the test run
-      - name: Analyze Bazel profile
-        if: always()
-        shell: pwsh
-        run: |
-          if (Test-Path "$env:BAZEL_PROFILE_JSON") {
-            bazelisk analyze-profile "$env:BAZEL_PROFILE_JSON"
-          }
-
       # Upload test logs
       - name: Upload test logs - Windows
         if: always()
diff --git a/python/tests/ci_windows_cppopts_test.py b/python/tests/ci_windows_cppopts_test.py
index 3fe1b5d9..79e0db21 100644
--- a/python/tests/ci_windows_cppopts_test.py
+++ b/python/tests/ci_windows_cppopts_test.py
@@ -385,7 +385,6 @@ def test_windows_ci_limits_scope_and_collects_profile(self) -> None:
         self.assertNotIn("bazelisk fetch //...", text)
         self.assertNotIn("bazelisk test --verbose_failures //...", text)
         self.assertNotIn("bazelisk build --config=opt --verbose_failures //...", text)
-        self.assertIn("bazelisk analyze-profile", text)
         self.assertRegex(
             text,
             r"actions/cache@v4",