Fix the two CI failures that hit most runs since 2026-10-16

.github/actions/upgrade-azure-cli/action.yml

@@ -3,11 +3,30 @@ description: Upgrades Azure CLI on Linux and Windows runners
 runs:
   using: composite
   steps:
-    - name: Upgrade Azure CLI on Linux
+    # Azure CLI 2.91.0 runs on Python 3.14 and deadlocks intermittently on module import during
+    # long-running operations such as creating a Service Bus namespace (Azure/azure-cli#33996). The fix,
+    # Azure/azure-cli#34201, is not in 2.91.0. Both steps install 2.90.0 instead of the latest version.
+    # Once a release that contains the fix is available, restore the upgrade:
+    # Linux:   curl -fsSL 'https://azurecliprod.blob.core.windows.net/$root/deb_install.sh' | sudo bash
+    # Windows: az upgrade --yes
+    - name: Install Azure CLI 2.90.0 on Linux
       if: runner.os == 'Linux'
       shell: bash
-      run: curl -fsSL 'https://azurecliprod.blob.core.windows.net/$root/deb_install.sh' | sudo bash
-    - name: Upgrade Azure CLI on Windows
+      run: |
+        deb="azure-cli_2.90.0-1~$(lsb_release -cs)_amd64.deb"
+        curl -fsSL -o "$RUNNER_TEMP/$deb" "https://packages.microsoft.com/repos/azure-cli/pool/main/a/azure-cli/$deb"
+        sudo apt-get install -y --allow-downgrades "$RUNNER_TEMP/$deb"
+        az version
+    # The MSI refuses to install over the newer version on the runner image, so the ZIP distribution is
+    # extracted next to it and put first on PATH for the following steps.
+    - name: Install Azure CLI 2.90.0 on Windows
       if: runner.os == 'Windows'
       shell: pwsh
-      run: az upgrade --yes
+      run: |
+        $zip = Join-Path $env:RUNNER_TEMP 'azure-cli-2.90.0-x64.zip'
+        $dir = Join-Path $env:RUNNER_TEMP 'azure-cli-2.90.0'
+        Invoke-WebRequest -Uri 'https://azcliprod.blob.core.windows.net/zip/azure-cli-2.90.0-x64.zip' -OutFile $zip
+        Expand-Archive -Path $zip -DestinationPath $dir -Force
+        $bin = Join-Path $dir 'bin'
+        $bin | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
+        & (Join-Path $bin 'az.cmd') version

src/ServiceControlInstaller.Engine.UnitTests/Validation/PackagedRavenDBTests.cs

@@ -77,9 +77,18 @@ await store.Maintenance.SendAsync(new PutIndexesOperation(new IndexDefinition
             finally
             {
                 await StopServer();
-                if (Directory.Exists(root))
+                try
+                {
+                    if (Directory.Exists(root))
+                    {
+                        FileUtils.DeleteDirectory(root, recursive: true, contentsOnly: false);
+                    }
+                }
+                catch (Exception ex)
                 {
-                    FileUtils.DeleteDirectory(root, recursive: true, contentsOnly: false);
+                    // The server files can stay locked for a moment after the process exits. The temp folder is not
+                    // what the test verifies, so a failed cleanup must not fail the test.
+                    Assert.Warn($"Failed to delete {root}: {ex}");
                 }
             }
 

src/ServiceControlInstaller.Engine/FileSystem/FileUtils.cs

@@ -179,7 +179,9 @@ static void RunWithRetries(Action action)
                     action();
                     break;
                 }
-                catch (IOException ex) when (--attempts > 0)
+                // Windows reports a file that a process still holds, or that an antivirus scanner holds, as
+                // UnauthorizedAccessException, for example right after the process that loaded it exits
+                catch (Exception ex) when ((ex is IOException or UnauthorizedAccessException) && --attempts > 0)
                 {
                     Debug.WriteLine($"ServiceControlInstaller.Engine.FileSystem.FileUtils::RunWithRetries Action failed, {attempts} attempts remaining. Reason: {ex.Message} ({ex.GetType().FullName})");
                     // Yes, Task.Delay would be better but would require all calls to be async