From 07d46983c72e5b7c07111543093a3179707bc268 Mon Sep 17 00:00:00 2001
From: Michael Nebel <michaelnebel@github.com>
Date: Tue, 15 Sep 2026 09:47:58 +0200
Subject: [PATCH 1/2] C#: Add extraction test for .NET 11 RC1.

---
 .../all-platforms/dotnet_11/Program.cs                 |  1 +
 .../all-platforms/dotnet_11/dotnet_build.csproj        | 10 ++++++++++
 .../all-platforms/dotnet_11/global.json                |  5 +++++
 .../integration-tests/all-platforms/dotnet_11/test.py  |  7 +++++++
 4 files changed, 23 insertions(+)
 create mode 100644 csharp/ql/integration-tests/all-platforms/dotnet_11/Program.cs
 create mode 100644 csharp/ql/integration-tests/all-platforms/dotnet_11/dotnet_build.csproj
 create mode 100644 csharp/ql/integration-tests/all-platforms/dotnet_11/global.json
 create mode 100644 csharp/ql/integration-tests/all-platforms/dotnet_11/test.py

diff --git a/csharp/ql/integration-tests/all-platforms/dotnet_11/Program.cs b/csharp/ql/integration-tests/all-platforms/dotnet_11/Program.cs
new file mode 100644
index 000000000000..bd44629f7e23
--- /dev/null
+++ b/csharp/ql/integration-tests/all-platforms/dotnet_11/Program.cs
@@ -0,0 +1 @@
+Console.WriteLine($"<arguments>{string.Join(",", args)}</arguments>");
diff --git a/csharp/ql/integration-tests/all-platforms/dotnet_11/dotnet_build.csproj b/csharp/ql/integration-tests/all-platforms/dotnet_11/dotnet_build.csproj
new file mode 100644
index 000000000000..5bf6c9b8cff2
--- /dev/null
+++ b/csharp/ql/integration-tests/all-platforms/dotnet_11/dotnet_build.csproj
@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net11.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>
diff --git a/csharp/ql/integration-tests/all-platforms/dotnet_11/global.json b/csharp/ql/integration-tests/all-platforms/dotnet_11/global.json
new file mode 100644
index 000000000000..f79f89df7d1a
--- /dev/null
+++ b/csharp/ql/integration-tests/all-platforms/dotnet_11/global.json
@@ -0,0 +1,5 @@
+{
+    "sdk": {
+        "version": "11.0.100-rc.1.26425.128"
+    }
+}
diff --git a/csharp/ql/integration-tests/all-platforms/dotnet_11/test.py b/csharp/ql/integration-tests/all-platforms/dotnet_11/test.py
new file mode 100644
index 000000000000..1f1fe52a4e5e
--- /dev/null
+++ b/csharp/ql/integration-tests/all-platforms/dotnet_11/test.py
@@ -0,0 +1,7 @@
+import pytest
+
+def test1(codeql, csharp):
+    codeql.database.create()
+
+def test2(codeql, csharp):
+    codeql.database.create(build_mode="none")

From 838685316d24e18ac665485f8f9d4bfd648d7040 Mon Sep 17 00:00:00 2001
From: Michael Nebel <michaelnebel@github.com>
Date: Tue, 15 Sep 2026 11:25:50 +0200
Subject: [PATCH 2/2] C#: Use the zip archive on windows runners, when
 downloading and installing .NET.

---
 .../DotNet.cs                                            | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DotNet.cs b/csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DotNet.cs
index babb811b25f0..f1cae33853a1 100644
--- a/csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DotNet.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DotNet.cs
@@ -280,9 +280,16 @@ private static BuildScript DownloadDotNetVersion(IBuildActions actions, ILogger
                     getInstall = version =>
                     {
                         var psCommand = $"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; &([scriptblock]::Create((Invoke-WebRequest -UseBasicParsing 'https://dot.net/v1/dotnet-install.ps1'))) -Version {version} -InstallDir {path}";
+                        var environment = new Dictionary<string, string>
+                        {
+                            // Starting with .NET 11, the installation script uses tar by default. However,
+                            // tar extraction fails in dotnet-install.ps1, so force the script to download
+                            // and extract the ZIP archive instead. This workaround may be removable in the future.
+                            {"DOTNET_INSTALL_SKIP_TAR", "1"}
+                        };
 
                         BuildScript GetInstall(string pwsh) =>
-                            new CommandBuilder(actions).
+                            new CommandBuilder(actions, environment: environment).
                             RunCommand(pwsh).
                             Argument("-NoProfile").
                             Argument("-ExecutionPolicy").