From b7b38247e016ed02c60ccd48e9a67b38da003de2 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman@google.com>
Date: Fri, 7 Nov 2025 21:18:19 +0000
Subject: [PATCH 1/8] [Github] Make Windows container use zstd

This enables much faster image unpack times. We benchmarked 20-30%
improvements when testing this initially. Use skopeo to copy the image
as it just works over the docker-archive/OCI container formats and does
not need to unpack the image to upload it.
---
 .../workflows/build-ci-container-windows.yml  | 22 +++++++++++--------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/build-ci-container-windows.yml b/.github/workflows/build-ci-container-windows.yml
index b6c46b70030ab..1be644077dca4 100644
--- a/.github/workflows/build-ci-container-windows.yml
+++ b/.github/workflows/build-ci-container-windows.yml
@@ -51,12 +51,12 @@ jobs:
           retention-days: 14
   
   push-ci-container:
-    if: github.event_name == 'push'
+    #if: github.event_name == 'push'
     needs:
       - build-ci-container-windows
-    permissions:
-      packages: write
-    runs-on: windows-2022
+    #permissions:
+    #  packages: write
+    runs-on: ubuntu-24.04
     env:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
@@ -66,8 +66,12 @@ jobs:
           name: container
       - name: Push Container
         run: |
-          docker load -i ${{ needs.build-ci-container-windows.outputs.container-filename }}
-          docker tag ${{ needs.build-ci-container-windows.outputs.container-name-tag }} ${{ needs.build-ci-container-windows.outputs.container-name }}:latest
-          docker login -u ${{ github.actor }} -p $env:GITHUB_TOKEN ghcr.io
-          docker push ${{ needs.build-ci-container-windows.outputs.container-name-tag }}
-          docker push ${{ needs.build-ci-container-windows.outputs.container-name }}:latest
+          sudo apt-get update
+          sudo apt-get install -y skopeo
+          skopeo login -u ${{ github.actor }} -p $env:GITHUB_TOKEN ghcr.io
+          skopeo copy ${{ needs.build-ci-container-windows.outputs.container-filename }} \
+            --additional-tags=latest \
+            --dest-compress-format zstd \
+            --dest-force-compress-format \
+            oci:/tmp/blah.tar
+            #docker://${{ needs.build-ci-container-windows.outputs.container-name-tag }}

From 90926c4a624d97663444bdc9183c137ae7efcb83 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman@google.com>
Date: Sat, 8 Nov 2025 05:08:31 +0000
Subject: [PATCH 2/8] testing

---
 .../workflows/build-ci-container-windows.yml  |   2 +-
 .../github-action-ci-windows/Dockerfile       | 144 +-----------------
 2 files changed, 3 insertions(+), 143 deletions(-)

diff --git a/.github/workflows/build-ci-container-windows.yml b/.github/workflows/build-ci-container-windows.yml
index 1be644077dca4..5b6d3a423d230 100644
--- a/.github/workflows/build-ci-container-windows.yml
+++ b/.github/workflows/build-ci-container-windows.yml
@@ -68,7 +68,7 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y skopeo
-          skopeo login -u ${{ github.actor }} -p $env:GITHUB_TOKEN ghcr.io
+          #skopeo login -u ${{ github.actor }} -p $env:GITHUB_TOKEN ghcr.io
           skopeo copy ${{ needs.build-ci-container-windows.outputs.container-filename }} \
             --additional-tags=latest \
             --dest-compress-format zstd \
diff --git a/.github/workflows/containers/github-action-ci-windows/Dockerfile b/.github/workflows/containers/github-action-ci-windows/Dockerfile
index f1e4f1538540b..09979985ab0e3 100644
--- a/.github/workflows/containers/github-action-ci-windows/Dockerfile
+++ b/.github/workflows/containers/github-action-ci-windows/Dockerfile
@@ -1,142 +1,2 @@
-# Agent image for LLVM org cluster.
-# .net 4.8 is required by chocolately package manager.
-FROM mcr.microsoft.com/dotnet/framework/sdk:4.8-windowsservercore-ltsc2022
-
-# Restore the default Windows shell for correct batch processing.
-SHELL ["cmd", "/S", "/C"]
-
-# Download the Build Tools bootstrapper.
-ADD https://aka.ms/vs/16/release/vs_buildtools.exe /TEMP/vs_buildtools.exe
-
-RUN powershell -Command Set-ExecutionPolicy Bypass -Scope Process -Force; [System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072; iex ((New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1'))
-
-# Download channel for fixed install.
-ARG CHANNEL_URL=https://aka.ms/vs/16/release/channel
-ADD ${CHANNEL_URL} /TEMP/VisualStudio.chman
-
-# Install Build Tools with C++ workload.
-#   - Documentation for docker installation
-#     https://docs.microsoft.com/en-us/visualstudio/install/build-tools-container?view=vs-2019
-#   - Documentation on workloads
-#     https://docs.microsoft.com/en-us/visualstudio/install/workload-component-id-vs-build-tools?view=vs-2019#c-build-tools
-#   - Documentation on flags
-#     https://docs.microsoft.com/en-us/visualstudio/install/use-command-line-parameters-to-install-visual-studio?view=vs-2019
-RUN /TEMP/vs_buildtools.exe --quiet --wait --norestart --nocache \
-    --channelUri C:\TEMP\VisualStudio.chman \
-    --installChannelUri C:\TEMP\VisualStudio.chman \
-    --installPath C:\BuildTools \
-    --add Microsoft.VisualStudio.Workload.VCTools \
-    --add Microsoft.VisualStudio.Component.VC.ATL \
-    --includeRecommended \
-    || IF "%ERRORLEVEL%"=="3010" EXIT 0
-
-# Register DIA dll (Debug Interface Access) so it can be used to symbolize
-# the stack traces. Register dll for 32 and 64 bit.
-# see https://developercommunity.visualstudio.com/content/problem/290674/msdia140dll-is-not-registered-on-vs2017-hosts.html
-
-RUN regsvr32 /S "C:\BuildTools\DIA SDK\bin\amd64\msdia140.dll" & \
-    regsvr32 /S "C:\BuildTools\DIA SDK\bin\msdia140.dll"
-
-# install tools as described in https://llvm.org/docs/GettingStartedVS.html
-# and a few more that were not documented...
-# Pin an older version of Python; the current Python 3.10 fails when
-# doing "pip install" for the other dependencies, as it fails to find libxml
-# while compiling some package.
-# We version pin the other packages as well to ensure the container build is as
-# reproducible as possible to prevent issues when upgrading only part of the
-# container.
-RUN choco install -y ninja --version 1.13.1 && \
-    choco install -y git --version 2.50.1 && \
-    choco install -y sccache --version 0.10.0 && \
-    choco install -y python3 --version 3.9.7
-
-# Testing requires psutil
-RUN pip install psutil
-
-# configure Python encoding
-ENV PYTHONIOENCODING=UTF-8
-
-# update the path variable
-# C:\Program Files\Git\usr\bin contains a usable bash and other unix tools.
-# C:\llvm-mingw\bin contains Clang configured for mingw targets and
-#     corresponding sysroots. Both the 'llvm' package (with Clang defaulting
-#     to MSVC targets) and this directory contains executables named
-#     'clang.exe' - add this last to let the other one have precedence.
-#     To use these compilers, use the triple prefixed form, e.g.
-#     x86_64-w64-mingw32-clang.
-# C:\buildtools and SDK paths are ones that are set by c:\BuildTools\Common7\Tools\VsDevCmd.bat -arch=amd64 -host_arch=amd64
-RUN powershell -Command \
-    [System.Environment]::SetEnvironmentVariable('PATH', \
-    [System.Environment]::GetEnvironmentVariable('PATH', 'machine') + ';C:\Program Files\Git\usr\bin;C:\llvm-mingw\bin' \
-    + ';C:\BuildTools\Common7\IDE\' \
-    + ';C:\BuildTools\Common7\IDE\CommonExt ensions\Microsoft\TeamFoundation\Team Explorer' \
-    + ';C:\BuildTools\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin' \
-    + ';C:\BuildTools\Common7\IDE\CommonExtensions\Microsoft\CMake\Ninja' \
-    + ';C:\BuildTools\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer' \
-    + ';C:\BuildTools\Common7\IDE\CommonExtensions\Microsoft\TestWindow' \
-    + ';C:\BuildTools\Common7\IDE\VC\VCPackages' \
-    + ';C:\BuildTools\Common7\Tools\' \
-    + ';C:\BuildTools\Common7\Tools\devinit' \
-    + ';C:\BuildTools\MSBuild\Current\Bin' \
-    + ';C:\BuildTools\MSBuild\Current\bin\Roslyn' \
-    + ';C:\BuildTools\VC\Tools\MSVC\14.29.30133\bin\HostX64\x64' \
-    + ';C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.8 Tools\x64\' \
-    + ';C:\Program Files (x86)\Windows Kits\10\bin\10.0.19041.0\x64' \
-    + ';C:\Program Files (x86)\Windows Kits\10\bin\x64' \
-    + ';C:\Windows\Microsoft.NET\Framework64\v4.0.30319' \
-    ,'machine')
-
-# support long file names during git checkout
-RUN git config --system core.longpaths true & \
-    git config --global core.autocrlf false
-
-ARG RUNNER_VERSION=2.329.0
-ENV RUNNER_VERSION=$RUNNER_VERSION
-
-RUN powershell -Command \
-    Invoke-WebRequest -Uri https://github.com/actions/runner/releases/download/v${env:RUNNER_VERSION}/actions-runner-win-x64-${env:RUNNER_VERSION}.zip -OutFile actions-runner-win.zip ; \
-    Add-Type -AssemblyName System.IO.Compression.FileSystem ; \
-    [System.IO.Compression.ZipFile]::ExtractToDirectory('actions-runner-win.zip', $PWD) ;\
-    rm actions-runner-win.zip
-
-# Set the LLVM_VERSION environment variable
-ENV LLVM_VERSION=21.1.2
-
-# Download and extract Clang compiler.
-# Create directories, download, extract, and clean up all in one layer
-RUN powershell -Command \
-    # --- Setup directories --- \
-    Write-Host "Creating directories..."; \
-    New-Item -Path "C:\temp-download" -ItemType "Directory" -Force ; \
-    New-Item -Path "C:\xz-utils" -ItemType "Directory" -Force ; \
-    New-Item -Path "C:\clang" -ItemType "Directory" -Force ; \
-    # --- 1. Download and extract xz --- \
-    Set-Location C:\temp-download ; \
-    Invoke-WebRequest -Uri "http://github.com/tukaani-project/xz/releases/download/v5.8.1/xz-5.8.1-windows.zip" -OutFile "xz.zip"; \
-    (Get-FileHash -Path "C:\temp-download\xz.zip" -Algorithm MD5).Hash -eq 'c3c69fdce3e825cc0b76123b36b0bcc2' ; \
-    Add-Type -AssemblyName "System.IO.Compression.FileSystem"; \
-    [System.IO.Compression.ZipFile]::ExtractToDirectory('C:\temp-download\xz.zip', 'C:\xz-utils'); \ 
-    # --- 2. Download and decompress Clang --- \
-    Invoke-WebRequest -Uri "http://github.com/llvm/llvm-project/releases/download/llvmorg-21.1.2/clang+llvm-21.1.2-x86_64-pc-windows-msvc.tar.xz" -OutFile "clang+llvm-21.1.2-x86_64-pc-windows-msvc.tar.xz" ; \
-    (Get-FileHash -Path "C:\temp-download\clang+llvm-21.1.2-x86_64-pc-windows-msvc.tar.xz" -Algorithm MD5).Hash -eq '0ae1d3effd9ab9d323f7fa595777f0a2' ; \
-    C:\xz-utils\bin_x86-64\xz.exe -d -qq clang+llvm-21.1.2-x86_64-pc-windows-msvc.tar.xz ; \
-    # --- 3. Extract clang --- \
-    C:\Windows\System32\tar.exe -xf clang+llvm-21.1.2-x86_64-pc-windows-msvc.tar -C C:\clang ; \
-    # --- 4. Clean up --- \
-    Set-Location C:\ ; \
-    Remove-Item C:\temp-download -Recurse -Force; \
-    Remove-Item C:\xz-utils -Recurse -Force; \
-    # -- 5. Shorten path to clang files & remove unnecessary files -- \
-    Set-Location C:\clang ; \
-    Rename-Item -Path "C:\clang\clang+llvm-21.1.2-x86_64-pc-windows-msvc" -NewName "C:\clang\clang-msvc" ; \
-    Set-Location C:\clang\clang-msvc ; \
-    Remove-Item -Path C:\clang\clang-msvc\libexec -Recurse -Force ; \
-    Remove-Item -Path C:\clang\clang-msvc\share -Recurse -Force ; \
-    Rename-Item -Path "C:\clang\clang-msvc\bin" -NewName "C:\clang\clang-msvc\bin-full" ; \
-    New-Item -Path "C:\clang\clang-msvc\bin" -ItemType Directory -Force ; \
-    Set-Location C:\clang\clang-msvc\bin ; \
-    Copy-Item -Path C:\clang\clang-msvc\bin-full\*.dll -Destination C:\clang\clang-msvc\bin\. ; \
-    Copy-Item -Path C:\clang\clang-msvc\bin-full\clang-cl.exe -Destination C:\clang\clang-msvc\bin\. ; \
-    Copy-Item -Path C:\clang\clang-msvc\bin-full\lld-link.exe -Destination C:\clang\clang-msvc\bin\. ; \
-    Set-Location C:\clang\clang-msvc ; \
-    Remove-Item -Path C:\clang\clang-msvc\bin-full -Recurse -Force ;
+FROM mcr.microsoft.com/windows/servercore:ltsc2022
+RUN echo test

From d5ee04d9c3a52524d3634f86fed3c8d7bb3599d2 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman@google.com>
Date: Sat, 8 Nov 2025 05:20:01 +0000
Subject: [PATCH 3/8] test

---
 .github/workflows/build-ci-container-windows.yml                | 2 +-
 .../workflows/containers/github-action-ci-windows/Dockerfile    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/build-ci-container-windows.yml b/.github/workflows/build-ci-container-windows.yml
index 5b6d3a423d230..2e7995711a170 100644
--- a/.github/workflows/build-ci-container-windows.yml
+++ b/.github/workflows/build-ci-container-windows.yml
@@ -70,7 +70,7 @@ jobs:
           sudo apt-get install -y skopeo
           #skopeo login -u ${{ github.actor }} -p $env:GITHUB_TOKEN ghcr.io
           skopeo copy ${{ needs.build-ci-container-windows.outputs.container-filename }} \
-            --additional-tags=latest \
+            --additional-tag=latest \
             --dest-compress-format zstd \
             --dest-force-compress-format \
             oci:/tmp/blah.tar
diff --git a/.github/workflows/containers/github-action-ci-windows/Dockerfile b/.github/workflows/containers/github-action-ci-windows/Dockerfile
index 09979985ab0e3..aaa1828549cef 100644
--- a/.github/workflows/containers/github-action-ci-windows/Dockerfile
+++ b/.github/workflows/containers/github-action-ci-windows/Dockerfile
@@ -1,2 +1,2 @@
-FROM mcr.microsoft.com/windows/servercore:ltsc2022
+FROM mcr.microsoft.com/windows/nanoserver:ltsc2022
 RUN echo test

From d0a5b8f34f8206a93d41085ded9c8c60183a691b Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman@google.com>
Date: Sat, 8 Nov 2025 05:22:36 +0000
Subject: [PATCH 4/8] test

---
 .github/workflows/build-ci-container-windows.yml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.github/workflows/build-ci-container-windows.yml b/.github/workflows/build-ci-container-windows.yml
index 2e7995711a170..d3772a3165ecf 100644
--- a/.github/workflows/build-ci-container-windows.yml
+++ b/.github/workflows/build-ci-container-windows.yml
@@ -72,6 +72,5 @@ jobs:
           skopeo copy ${{ needs.build-ci-container-windows.outputs.container-filename }} \
             --additional-tag=latest \
             --dest-compress-format zstd \
-            --dest-force-compress-format \
             oci:/tmp/blah.tar
             #docker://${{ needs.build-ci-container-windows.outputs.container-name-tag }}

From 4d9325c2c2430cf78ebaf7a3cd2eab80a29445ad Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman@google.com>
Date: Sat, 8 Nov 2025 05:25:42 +0000
Subject: [PATCH 5/8] test

---
 .github/workflows/build-ci-container-windows.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build-ci-container-windows.yml b/.github/workflows/build-ci-container-windows.yml
index d3772a3165ecf..01af5fdf52866 100644
--- a/.github/workflows/build-ci-container-windows.yml
+++ b/.github/workflows/build-ci-container-windows.yml
@@ -69,7 +69,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y skopeo
           #skopeo login -u ${{ github.actor }} -p $env:GITHUB_TOKEN ghcr.io
-          skopeo copy ${{ needs.build-ci-container-windows.outputs.container-filename }} \
+          skopeo copy docker-archive:${{ needs.build-ci-container-windows.outputs.container-filename }} \
             --additional-tag=latest \
             --dest-compress-format zstd \
             oci:/tmp/blah.tar

From 8e4d44e3957d5196038a7226cee0385af795ccc5 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman@google.com>
Date: Sun, 9 Nov 2025 04:07:13 +0000
Subject: [PATCH 6/8] test

---
 .github/workflows/build-ci-container-windows.yml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/.github/workflows/build-ci-container-windows.yml b/.github/workflows/build-ci-container-windows.yml
index 01af5fdf52866..119b137867397 100644
--- a/.github/workflows/build-ci-container-windows.yml
+++ b/.github/workflows/build-ci-container-windows.yml
@@ -68,9 +68,8 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y skopeo
-          #skopeo login -u ${{ github.actor }} -p $env:GITHUB_TOKEN ghcr.io
+          #skopeo login -u ${{ github.actor }} -p ${{ secrets.GITHUB_TOKEN }} ghcr.io
           skopeo copy docker-archive:${{ needs.build-ci-container-windows.outputs.container-filename }} \
-            --additional-tag=latest \
             --dest-compress-format zstd \
             oci:/tmp/blah.tar
             #docker://${{ needs.build-ci-container-windows.outputs.container-name-tag }}

From c67ded2622454bd9631d8892cd25dc7fc55421c7 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman@google.com>
Date: Sun, 9 Nov 2025 04:11:51 +0000
Subject: [PATCH 7/8] test

---
 .../workflows/build-ci-container-windows.yml  | 20 ++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/build-ci-container-windows.yml b/.github/workflows/build-ci-container-windows.yml
index 119b137867397..e2ea18728df33 100644
--- a/.github/workflows/build-ci-container-windows.yml
+++ b/.github/workflows/build-ci-container-windows.yml
@@ -5,8 +5,8 @@ permissions:
 
 on:
   push:
-    branches:
-      - main
+    #branches:
+    #  - main
     paths:
       - .github/workflows/build-ci-container-windows.yml
       - '.github/workflows/containers/github-action-ci-windows/**'
@@ -17,7 +17,7 @@ on:
 
 jobs:
   build-ci-container-windows:
-    if: github.repository_owner == 'llvm'
+    #if: github.repository_owner == 'llvm'
     runs-on: windows-2022
     outputs:
       container-name: ${{ steps.vars.outputs.container-name }}
@@ -51,11 +51,11 @@ jobs:
           retention-days: 14
   
   push-ci-container:
-    #if: github.event_name == 'push'
+    if: github.event_name == 'push'
     needs:
       - build-ci-container-windows
-    #permissions:
-    #  packages: write
+    permissions:
+      packages: write
     runs-on: ubuntu-24.04
     env:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -68,8 +68,10 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y skopeo
-          #skopeo login -u ${{ github.actor }} -p ${{ secrets.GITHUB_TOKEN }} ghcr.io
+          skopeo login -u ${{ github.actor }} -p ${{ secrets.GITHUB_TOKEN }} ghcr.io
           skopeo copy docker-archive:${{ needs.build-ci-container-windows.outputs.container-filename }} \
             --dest-compress-format zstd \
-            oci:/tmp/blah.tar
-            #docker://${{ needs.build-ci-container-windows.outputs.container-name-tag }}
+            docker://${{ needs.build-ci-container-windows.outputs.container-name-tag }}
+          skopeo copy docker-archive:${{ needs.build-ci-container-windows.outputs.container-filename }} \
+            --dest-compress-format zstd \
+            docker://${{ needs.build-ci-container-windows.outputs.container-name }}:latest

From 85cda71a1ee988a9bad8cbaa850c63dc820e9da8 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman@google.com>
Date: Sun, 9 Nov 2025 04:15:35 +0000
Subject: [PATCH 8/8] finish up

---
 .../workflows/build-ci-container-windows.yml  |   6 +-
 .../github-action-ci-windows/Dockerfile       | 144 +++++++++++++++++-
 2 files changed, 145 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/build-ci-container-windows.yml b/.github/workflows/build-ci-container-windows.yml
index e2ea18728df33..3996948bb44e0 100644
--- a/.github/workflows/build-ci-container-windows.yml
+++ b/.github/workflows/build-ci-container-windows.yml
@@ -5,8 +5,8 @@ permissions:
 
 on:
   push:
-    #branches:
-    #  - main
+    branches:
+      - main
     paths:
       - .github/workflows/build-ci-container-windows.yml
       - '.github/workflows/containers/github-action-ci-windows/**'
@@ -17,7 +17,7 @@ on:
 
 jobs:
   build-ci-container-windows:
-    #if: github.repository_owner == 'llvm'
+    if: github.repository_owner == 'llvm'
     runs-on: windows-2022
     outputs:
       container-name: ${{ steps.vars.outputs.container-name }}
diff --git a/.github/workflows/containers/github-action-ci-windows/Dockerfile b/.github/workflows/containers/github-action-ci-windows/Dockerfile
index aaa1828549cef..f1e4f1538540b 100644
--- a/.github/workflows/containers/github-action-ci-windows/Dockerfile
+++ b/.github/workflows/containers/github-action-ci-windows/Dockerfile
@@ -1,2 +1,142 @@
-FROM mcr.microsoft.com/windows/nanoserver:ltsc2022
-RUN echo test
+# Agent image for LLVM org cluster.
+# .net 4.8 is required by chocolately package manager.
+FROM mcr.microsoft.com/dotnet/framework/sdk:4.8-windowsservercore-ltsc2022
+
+# Restore the default Windows shell for correct batch processing.
+SHELL ["cmd", "/S", "/C"]
+
+# Download the Build Tools bootstrapper.
+ADD https://aka.ms/vs/16/release/vs_buildtools.exe /TEMP/vs_buildtools.exe
+
+RUN powershell -Command Set-ExecutionPolicy Bypass -Scope Process -Force; [System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072; iex ((New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1'))
+
+# Download channel for fixed install.
+ARG CHANNEL_URL=https://aka.ms/vs/16/release/channel
+ADD ${CHANNEL_URL} /TEMP/VisualStudio.chman
+
+# Install Build Tools with C++ workload.
+#   - Documentation for docker installation
+#     https://docs.microsoft.com/en-us/visualstudio/install/build-tools-container?view=vs-2019
+#   - Documentation on workloads
+#     https://docs.microsoft.com/en-us/visualstudio/install/workload-component-id-vs-build-tools?view=vs-2019#c-build-tools
+#   - Documentation on flags
+#     https://docs.microsoft.com/en-us/visualstudio/install/use-command-line-parameters-to-install-visual-studio?view=vs-2019
+RUN /TEMP/vs_buildtools.exe --quiet --wait --norestart --nocache \
+    --channelUri C:\TEMP\VisualStudio.chman \
+    --installChannelUri C:\TEMP\VisualStudio.chman \
+    --installPath C:\BuildTools \
+    --add Microsoft.VisualStudio.Workload.VCTools \
+    --add Microsoft.VisualStudio.Component.VC.ATL \
+    --includeRecommended \
+    || IF "%ERRORLEVEL%"=="3010" EXIT 0
+
+# Register DIA dll (Debug Interface Access) so it can be used to symbolize
+# the stack traces. Register dll for 32 and 64 bit.
+# see https://developercommunity.visualstudio.com/content/problem/290674/msdia140dll-is-not-registered-on-vs2017-hosts.html
+
+RUN regsvr32 /S "C:\BuildTools\DIA SDK\bin\amd64\msdia140.dll" & \
+    regsvr32 /S "C:\BuildTools\DIA SDK\bin\msdia140.dll"
+
+# install tools as described in https://llvm.org/docs/GettingStartedVS.html
+# and a few more that were not documented...
+# Pin an older version of Python; the current Python 3.10 fails when
+# doing "pip install" for the other dependencies, as it fails to find libxml
+# while compiling some package.
+# We version pin the other packages as well to ensure the container build is as
+# reproducible as possible to prevent issues when upgrading only part of the
+# container.
+RUN choco install -y ninja --version 1.13.1 && \
+    choco install -y git --version 2.50.1 && \
+    choco install -y sccache --version 0.10.0 && \
+    choco install -y python3 --version 3.9.7
+
+# Testing requires psutil
+RUN pip install psutil
+
+# configure Python encoding
+ENV PYTHONIOENCODING=UTF-8
+
+# update the path variable
+# C:\Program Files\Git\usr\bin contains a usable bash and other unix tools.
+# C:\llvm-mingw\bin contains Clang configured for mingw targets and
+#     corresponding sysroots. Both the 'llvm' package (with Clang defaulting
+#     to MSVC targets) and this directory contains executables named
+#     'clang.exe' - add this last to let the other one have precedence.
+#     To use these compilers, use the triple prefixed form, e.g.
+#     x86_64-w64-mingw32-clang.
+# C:\buildtools and SDK paths are ones that are set by c:\BuildTools\Common7\Tools\VsDevCmd.bat -arch=amd64 -host_arch=amd64
+RUN powershell -Command \
+    [System.Environment]::SetEnvironmentVariable('PATH', \
+    [System.Environment]::GetEnvironmentVariable('PATH', 'machine') + ';C:\Program Files\Git\usr\bin;C:\llvm-mingw\bin' \
+    + ';C:\BuildTools\Common7\IDE\' \
+    + ';C:\BuildTools\Common7\IDE\CommonExt ensions\Microsoft\TeamFoundation\Team Explorer' \
+    + ';C:\BuildTools\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin' \
+    + ';C:\BuildTools\Common7\IDE\CommonExtensions\Microsoft\CMake\Ninja' \
+    + ';C:\BuildTools\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer' \
+    + ';C:\BuildTools\Common7\IDE\CommonExtensions\Microsoft\TestWindow' \
+    + ';C:\BuildTools\Common7\IDE\VC\VCPackages' \
+    + ';C:\BuildTools\Common7\Tools\' \
+    + ';C:\BuildTools\Common7\Tools\devinit' \
+    + ';C:\BuildTools\MSBuild\Current\Bin' \
+    + ';C:\BuildTools\MSBuild\Current\bin\Roslyn' \
+    + ';C:\BuildTools\VC\Tools\MSVC\14.29.30133\bin\HostX64\x64' \
+    + ';C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.8 Tools\x64\' \
+    + ';C:\Program Files (x86)\Windows Kits\10\bin\10.0.19041.0\x64' \
+    + ';C:\Program Files (x86)\Windows Kits\10\bin\x64' \
+    + ';C:\Windows\Microsoft.NET\Framework64\v4.0.30319' \
+    ,'machine')
+
+# support long file names during git checkout
+RUN git config --system core.longpaths true & \
+    git config --global core.autocrlf false
+
+ARG RUNNER_VERSION=2.329.0
+ENV RUNNER_VERSION=$RUNNER_VERSION
+
+RUN powershell -Command \
+    Invoke-WebRequest -Uri https://github.com/actions/runner/releases/download/v${env:RUNNER_VERSION}/actions-runner-win-x64-${env:RUNNER_VERSION}.zip -OutFile actions-runner-win.zip ; \
+    Add-Type -AssemblyName System.IO.Compression.FileSystem ; \
+    [System.IO.Compression.ZipFile]::ExtractToDirectory('actions-runner-win.zip', $PWD) ;\
+    rm actions-runner-win.zip
+
+# Set the LLVM_VERSION environment variable
+ENV LLVM_VERSION=21.1.2
+
+# Download and extract Clang compiler.
+# Create directories, download, extract, and clean up all in one layer
+RUN powershell -Command \
+    # --- Setup directories --- \
+    Write-Host "Creating directories..."; \
+    New-Item -Path "C:\temp-download" -ItemType "Directory" -Force ; \
+    New-Item -Path "C:\xz-utils" -ItemType "Directory" -Force ; \
+    New-Item -Path "C:\clang" -ItemType "Directory" -Force ; \
+    # --- 1. Download and extract xz --- \
+    Set-Location C:\temp-download ; \
+    Invoke-WebRequest -Uri "http://github.com/tukaani-project/xz/releases/download/v5.8.1/xz-5.8.1-windows.zip" -OutFile "xz.zip"; \
+    (Get-FileHash -Path "C:\temp-download\xz.zip" -Algorithm MD5).Hash -eq 'c3c69fdce3e825cc0b76123b36b0bcc2' ; \
+    Add-Type -AssemblyName "System.IO.Compression.FileSystem"; \
+    [System.IO.Compression.ZipFile]::ExtractToDirectory('C:\temp-download\xz.zip', 'C:\xz-utils'); \ 
+    # --- 2. Download and decompress Clang --- \
+    Invoke-WebRequest -Uri "http://github.com/llvm/llvm-project/releases/download/llvmorg-21.1.2/clang+llvm-21.1.2-x86_64-pc-windows-msvc.tar.xz" -OutFile "clang+llvm-21.1.2-x86_64-pc-windows-msvc.tar.xz" ; \
+    (Get-FileHash -Path "C:\temp-download\clang+llvm-21.1.2-x86_64-pc-windows-msvc.tar.xz" -Algorithm MD5).Hash -eq '0ae1d3effd9ab9d323f7fa595777f0a2' ; \
+    C:\xz-utils\bin_x86-64\xz.exe -d -qq clang+llvm-21.1.2-x86_64-pc-windows-msvc.tar.xz ; \
+    # --- 3. Extract clang --- \
+    C:\Windows\System32\tar.exe -xf clang+llvm-21.1.2-x86_64-pc-windows-msvc.tar -C C:\clang ; \
+    # --- 4. Clean up --- \
+    Set-Location C:\ ; \
+    Remove-Item C:\temp-download -Recurse -Force; \
+    Remove-Item C:\xz-utils -Recurse -Force; \
+    # -- 5. Shorten path to clang files & remove unnecessary files -- \
+    Set-Location C:\clang ; \
+    Rename-Item -Path "C:\clang\clang+llvm-21.1.2-x86_64-pc-windows-msvc" -NewName "C:\clang\clang-msvc" ; \
+    Set-Location C:\clang\clang-msvc ; \
+    Remove-Item -Path C:\clang\clang-msvc\libexec -Recurse -Force ; \
+    Remove-Item -Path C:\clang\clang-msvc\share -Recurse -Force ; \
+    Rename-Item -Path "C:\clang\clang-msvc\bin" -NewName "C:\clang\clang-msvc\bin-full" ; \
+    New-Item -Path "C:\clang\clang-msvc\bin" -ItemType Directory -Force ; \
+    Set-Location C:\clang\clang-msvc\bin ; \
+    Copy-Item -Path C:\clang\clang-msvc\bin-full\*.dll -Destination C:\clang\clang-msvc\bin\. ; \
+    Copy-Item -Path C:\clang\clang-msvc\bin-full\clang-cl.exe -Destination C:\clang\clang-msvc\bin\. ; \
+    Copy-Item -Path C:\clang\clang-msvc\bin-full\lld-link.exe -Destination C:\clang\clang-msvc\bin\. ; \
+    Set-Location C:\clang\clang-msvc ; \
+    Remove-Item -Path C:\clang\clang-msvc\bin-full -Recurse -Force ;