[main] Bump Microsoft.CodeAnalysis from 3.11.0 to 5.9.0

[dependabot]

Updated Microsoft.CodeAnalysis from 3.11.0 to 5.9.0.

Release notes

Sourced from Microsoft.CodeAnalysis's releases.

5.0.4

Release

5.0.2

Release Notes
Install Instructions

Repos

• Core

5.0.1

Release Notes
Install Instructions

Repo

• Core

4.2.0-4.22266.5

Release

4.2.0-3.22151.16

Release

4.2.0-1.22108.11

Release

4.0.0-2.21354.7

Release

4.0.0-2.21254.26

Release

4.0.0-1.21277.15

Release

Commits viewable in compare view.

[Copilot]

Pull request overview

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Updates the centrally managed Roslyn (Microsoft.CodeAnalysis) version used across the repo.

Changes:

• Bumped MicrosoftCodeAnalysisVersion from 3.11.0 to 5.9.0.

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[github-actions]

🔍 Build Failure Analysis

Summary — All 9 build legs fail identically during NuGet restore with NU1605 (package downgrade promoted to error), because this PR bumps MicrosoftCodeAnalysisVersion to 5.9.0 without raising the pinned Microsoft.CodeAnalysis.Analyzers version to match.

Root cause 1: Microsoft.CodeAnalysis.Analyzers pin is now lower than what Microsoft.CodeAnalysis.Common/Microsoft.CodeAnalysis.CSharp.Workspaces 5.9.0 require

This PR raises MicrosoftCodeAnalysisVersion from 3.11.0 to 5.9.0 in Directory.Packages.props. Microsoft.CodeAnalysis.Common 5.9.0 and Microsoft.CodeAnalysis.CSharp.Workspaces 5.9.0 both transitively require Microsoft.CodeAnalysis.Analyzers >= 5.9.0-1.26328.17, but Directory.Packages.props still pins the direct Microsoft.CodeAnalysis.Analyzers PackageVersion at 5.6.0. NuGet resolves this as a downgrade (5.9.0-1.26328.17 → 5.6.0) for the two analyzer projects that reference it, and warnings-as-errors promotes the resulting NU1605 to a restore error, so all legs fail before compilation even starts.

Affected files / errors

• Directory.Packages.props:30 — MicrosoftCodeAnalysisVersion bumped to 5.9.0; the Microsoft.CodeAnalysis.Analyzers pin was not raised alongside it
• src/Analyzers/MSTest.Analyzers/MSTest.Analyzers.csproj — NU1605: downgrade via Microsoft.CodeAnalysis.Common 5.9.0 -> Microsoft.CodeAnalysis.Analyzers (>= 5.9.0-1.26328.17)
• src/Analyzers/MSTest.Analyzers.CodeFixes/MSTest.Analyzers.CodeFixes.csproj — NU1605: downgrade via Microsoft.CodeAnalysis.CSharp.Workspaces 5.9.0 -> Microsoft.CodeAnalysis.Analyzers (>= 5.9.0-1.26328.17)

Proposed fix

Raise the Microsoft.CodeAnalysis.Analyzers PackageVersion to 5.9.0 (or at least 5.9.0-1.26328.17) so it is no longer lower than what Microsoft.CodeAnalysis.Common/CSharp.Workspaces 5.9.0 require:

-    <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="5.6.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="5.9.0" />

This root cause explains every reported error — the same two NU1605 errors repeat verbatim across all 9 legs (Linux, macOS, Windows Debug/Release, application-model acceptance), because restore fails identically on every platform before any leg-specific compilation begins.

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Build overview

• Failing target: Restore (RestoreTask) — package downgrade detected during NuGet restore
• Affected legs: Linux Release/Debug, macOS Release/Debug, Windows Debug (x2), Windows application-model acceptance Debug, Windows Release (x2) — 9/9 legs report the identical pair of errors
• No compilation errors observed on any leg — the failure is 100% a restore-time NU1605 promoted to error

All MSBuild errors (2 unique, repeated across all 9 legs)

Code	Project	Message
NU1605	MSTest.Analyzers.csproj	Downgrade: Microsoft.CodeAnalysis.Analyzers from 5.9.0-1.26328.17 to 5.6.0 (via Microsoft.CodeAnalysis.Common 5.9.0)
NU1605	MSTest.Analyzers.CodeFixes.csproj	Downgrade: Microsoft.CodeAnalysis.Analyzers from 5.9.0-1.26328.17 to 5.6.0 (via Microsoft.CodeAnalysis.CSharp.Workspaces 5.9.0)

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_{🤖 Generated by the Build Failure Analysis workflow using binlog-mcp · commit a4d8232}

🤖 Automated content by GitHub Copilot. Generated by the Build Failure Analysis workflow. · auto · 61.8 AIC · ⌖ 2.08 AIC · ⊞ 11.6K · [◷]( · ◷)

[github-actions]

🤖 Automated content by GitHub Copilot. Generated by the Build Failure Analysis workflow. · auto · 61.8 AIC · ⌖ 2.08 AIC · ⊞ 11.6K · ◷

[github-actions]

🔧 NU1605 — MicrosoftCodeAnalysisVersion is being bumped to 5.9.0 here, but the separately-pinned Microsoft.CodeAnalysis.Analyzers PackageVersion (elsewhere in this file, currently 5.6.0) is now lower than the >= 5.9.0-1.26328.17 required transitively by Microsoft.CodeAnalysis.Common/Microsoft.CodeAnalysis.CSharp.Workspaces 5.9.0. This causes an NU1605 downgrade error (promoted to a hard error) on every build leg. Raise the Microsoft.CodeAnalysis.Analyzers PackageVersion to 5.9.0 as well.

Suggested change

	<MicrosoftCodeAnalysisVersion>5.9.0</MicrosoftCodeAnalysisVersion>
	<MicrosoftCodeAnalysisVersion>5.9.0</MicrosoftCodeAnalysisVersion>

[Copilot]

Pull request overview

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[Amaury Levé (Evangelink)]

Closing because this update is not safe for the shipping MSTest analyzers.

The current CI run fails restore across all build legs with NU1605: Microsoft.CodeAnalysis.Common 5.9.0 requires Microsoft.CodeAnalysis.Analyzers >= 5.9.0-1.26328.17, while the repository pins 5.6.0.

More importantly, the changed property is used to compile the analyzer and code-fix DLLs shipped in MSTest.Analyzers and consumed through MSTest.TestFramework. Roslyn 5.x has a minimum supported host of Visual Studio 2026 18.0, so this would drop Visual Studio 2019 and 2022 analyzer compatibility. PrivateAssets does not prevent that host compatibility break because the compiled analyzer DLLs are shipped.

The shipping analyzer baseline should remain on Roslyn 3.11 unless dropping those Visual Studio versions is an explicit product decision. A newer Roslyn version needed only for development should use a separate version override.

[dependabot]

OK, I won't notify you again about this release, but will get in touch when a new version is available. If you'd rather skip all updates until the next major or minor version, let me know by commenting @dependabot ignore this major version or @dependabot ignore this minor version. You can also ignore all major, minor, or patch releases for a dependency by adding an ignore condition with the desired update_types to your config file.

If you change your mind, just re-open this PR and I'll resolve any conflicts on it.