dotnet-maestro · Sep 11, 2026 · Sep 11, 2026
diff --git a/src/roslyn/.github/skills/snap/SKILL.md b/src/roslyn/.github/skills/snap/SKILL.md
@@ -78,9 +78,9 @@ Identify the three named branches (`main`, `release/insiders`, `release/stable`)
 
 **Step B — Read versions and configs** from all three branches:
 - Fetch `eng/Versions.props` from each branch to get the current version.
-  - For roslyn: VS version = `Major + 13`.`Minor` (e.g., Roslyn 5.6 → VS 18.6).
+  - For roslyn: read `<MajorVersion>` and `<MinorVersion>`. `<VsMajorVersion>` is derived as Roslyn `MajorVersion + 13`, and `<VsMinorVersion>` is derived from Roslyn `<MinorVersion>` (e.g., Roslyn 5.6 → VS 18.6).
 - Razor versions are also in `eng/Versions.props` (same file as Roslyn's version), using `Razor`-prefixed property names. Razor has **two independent versions**:
-  - **Razor VSIX/Addin version**: use `<RazorVsixVersionPrefix>` directly (e.g., `18.8.1`). Tracks the Visual Studio version like the rest of the snap cascade. `<RazorAddinMajorVersion>` tracks the major.minor (e.g., `18.8`).
+  - **Razor VSIX/Addin version**: `<RazorVsixVersionPrefix>` and `<RazorAddinMajorVersion>` are derived from the shared `VsMajorVersion`/`VsMinorVersion` properties. They track the Visual Studio version like the rest of the snap cascade.
   - **Razor SDK version**: read `<RazorMajorVersion>` and `<RazorMinorVersion>` (e.g., `10.4`). Tracks the **.NET SDK band** Razor ships into, **not** the VS version. The mapping is `.NET <Major>.0.<Band>xx SDK` <-> Razor `<Major>.<Band>` (e.g., `.NET 10.0.4xx SDK` <-> Razor `10.4`, `.NET 11.0.1xx SDK` <-> Razor `11.1`).
   - Note: `src/Razor/Directory.Build.props` maps these `Razor`-prefixed properties to the standard MSBuild properties (`MajorVersion`, `MinorVersion`, etc.) for Razor projects. During a snap, only edit `eng/Versions.props` — the Razor props file should not need changes.
 - Fetch `eng/config/PublishData.json` from each branch to get insertion config (`vsBranch`, `insertionCreateDraftPR`, `insertionTitlePrefix`).
@@ -91,7 +91,7 @@ Identify the three named branches (`main`, `release/insiders`, `release/stable`)
 - Among those, locate the channel whose major matches the branch's current Razor `RazorMajorVersion`. If multiple channels of the same major are temporarily assigned (e.g., both `.NET 10.0.4xx SDK` and `.NET 10.0.5xx SDK`), pick the **lowest** band -- Razor is versioned to the lowest SDK band it ships into, since higher bands roll forward and can consume the same package.
 - Apply the mapping `.NET <Major>.0.<Band>xx SDK` -> expected Razor `<Major>.<Band>`.
 - If no matching SDK channel exists for that branch (common on `main` immediately after a previous snap, before the next SDK band channel has been created), record the branch as "no matching SDK channel -- Razor SDK version bump deferred".
-- If the expected version differs from the branch's current `RazorMajorVersion.RazorMinorVersion`, flag it as a drift to fix (during snap, see Phase 2 step 5b; during follow-up, see Phase 3 step 3.9).
+- If the expected version differs from the branch's current `RazorMajorVersion.RazorMinorVersion`, flag it as a drift to fix (during snap, see Phase 2 step 5; during follow-up, see Phase 3 step 3.9).
 
 **Step C — Infer the snap cascade** from the discovered state:
 - The snap version is whatever `main` currently targets (e.g., 18.6).
@@ -258,15 +258,11 @@ After gathering, present **all** planned actions in a numbered list for the user
 
 3. **Update `PublishData.json` on `main`**: Set `insertionCreateDraftPR` to `true`. Until the snapped version's scheduled VS `main` → `rel/insiders` snap, main's insertions should be drafts to avoid merging into the wrong VS branch. This change goes in the same PR as the version bump.
 
-4. **Update `Versions.props` on `main`**: Bump the minor version (e.g., 5.6.0 → 5.7.0) and reset `PreReleaseVersionLabel` to `1`.
+4. **Update `Versions.props` on `main`**: Bump the Roslyn minor version (e.g., 5.6.0 → 5.7.0) and reset `PreReleaseVersionLabel` to `1`. This automatically advances `VsMajorVersion`/`VsMinorVersion` and the derived Razor VSIX/Addin and EditorConfig component versions. Do not edit those derived properties.
 
-5. **Update Razor versions in `eng/Versions.props`** (roslyn only) -- Razor has two independent versions, both stored as `Razor`-prefixed properties in `eng/Versions.props`:
-
-   **5a. Razor VSIX/Addin version**: bump `<RazorVsixVersionPrefix>` and `<RazorAddinMajorVersion>` minor to track the new VS version (e.g., `18.7.1` -> `18.8.1`, `18.7` -> `18.8`). Always done as part of the snap.
-
-   **5b. Razor SDK version**: only update if the branch's SDK default-channel doesn't match the current `<RazorMajorVersion>.<RazorMinorVersion>`. Use the discovery from Phase 1 / Step B.1:
+5. **Update the Razor SDK version in `eng/Versions.props`** (roslyn only): Only update if the branch's SDK default-channel doesn't match the current `<RazorMajorVersion>.<RazorMinorVersion>`. Use the discovery from Phase 1 / Step B.1:
      - If `main` flows to `.NET <Major>.0.<Band>xx SDK` and `<Major>.<Band>` differs from the current `<RazorMajorVersion>.<RazorMinorVersion>` in `eng/Versions.props`, set `<RazorMajorVersion>` and `<RazorMinorVersion>` to match (e.g., `.NET 10.0.4xx SDK` -> `<RazorMajorVersion>10</RazorMajorVersion>`, `<RazorMinorVersion>4</RazorMinorVersion>`). Leave `<RazorPatchVersion>` as `0`.
-     - If no SDK channel matching Razor's current major exists on `main` yet (the next SDK band channel hasn't been created), **skip 5b** and add it to the post-VS-snap follow-up (step 3.9). Do **not** predict the next band -- only update when darc confirms the channel.
+     - If no SDK channel matching Razor's current major exists on `main` yet (the next SDK band channel hasn't been created), **skip this update** and add it to the post-VS-snap follow-up (step 3.9). Do **not** predict the next band -- only update when darc confirms the channel.
 
 6. **Update SARIF files** (roslyn only): Replace old version string with new version in all `.sarif` files under `src/RoslynAnalyzers/` (search recursively).
 
@@ -517,16 +513,14 @@ Find them with `git ls-files 'src/RoslynAnalyzers/**/*.sarif'` or search via the
 
 These SARIF files are generated and intentionally have no final newline. Perform a byte-preserving replacement: keep the existing encoding, BOM, line endings, and EOF state exactly. Do not deserialize/reserialize the JSON or append a newline. The correctness build regenerates these files and fails if any non-version bytes differ.
 
-**Razor versions in `eng/Versions.props`**: Two independent sets of edits in the Razor PropertyGroups. Read the current file, perform both replacements in memory, then PUT the new content back via the GitHub API.
+**Version properties in `eng/Versions.props`**: Update source properties and leave derived properties unchanged. Read the current file, perform the required replacements in memory, then PUT the new content back via the GitHub API.
 
-- **5a. VSIX/Addin version** -- bump the VS version (always done):
-  - `<RazorVsixVersionPrefix>{oldMajor.Minor}.1</RazorVsixVersionPrefix>` -> `<RazorVsixVersionPrefix>{newMajor.Minor}.1</RazorVsixVersionPrefix>` (e.g., `18.7.1` -> `18.8.1`)
-  - `<RazorAddinMajorVersion>{oldMajor.Minor}</RazorAddinMajorVersion>` -> `<RazorAddinMajorVersion>{newMajor.Minor}</RazorAddinMajorVersion>` (e.g., `18.7` -> `18.8`)
-- **5b. SDK RazorMajorVersion/RazorMinorVersion** -- only if the matching SDK channel exists on `main` and differs from the current value (see Phase 1 / Step B.1):
+- **Roslyn/VS version** -- bump `<MinorVersion>` and reset `<PreReleaseVersionLabel>` to `1`. `VsMajorVersion`, `VsMinorVersion`, `RazorVsixVersionPrefix`, `RazorAddinMajorVersion`, `EditorConfigVersionPrefix`, and `EditorConfigAssemblyVersion` are derived and must not be edited during a snap. Verify that they evaluate to the new VS train after the Roslyn bump.
+- **SDK RazorMajorVersion/RazorMinorVersion** -- only if the matching SDK channel exists on `main` and differs from the current value (see Phase 1 / Step B.1):
   - `<RazorMajorVersion>{old}</RazorMajorVersion>` -> `<RazorMajorVersion>{newSdkMajor}</RazorMajorVersion>` (only changes when crossing .NET majors, e.g., 10 -> 11)
   - `<RazorMinorVersion>{old}</RazorMinorVersion>` -> `<RazorMinorVersion>{newSdkBand}</RazorMinorVersion>` (e.g., `0` -> `4` when `main` flows to `.NET 10.0.4xx SDK`)
   - Leave `<RazorPatchVersion>0</RazorPatchVersion>` and `<RazorPreReleaseVersionLabel>` untouched.
-  - If no matching SDK channel exists on `main` yet (the next SDK band hasn't been created), **omit 5b from this PR** and add it to the post-VS-snap follow-up (Step 3.9).
+  - If no matching SDK channel exists on `main` yet (the next SDK band hasn't been created), omit this update from the PR and add it to the post-VS-snap follow-up (Step 3.9).
 
 #### 3.6 Update darc default channels and subscriptions
 
@@ -727,9 +721,9 @@ In the PR body/description, include a brief note such as `Auto-generated by snap
 
 Also handle any pending SDK channel follow-ups (e.g., adding `main` to a newly created `.NET 10.0.Nxx SDK` channel).
 
-**Deferred Razor SDK version bump** (roslyn only): If the Razor SDK version bump (Phase 2 step 5b) was deferred during the initial snap because no matching `.NET <Razor.RazorMajorVersion>.0.<Band>xx SDK` channel existed on `main` at the time, re-check now:
+**Deferred Razor SDK version bump** (roslyn only): If the Razor SDK version bump (Phase 2 step 5) was deferred during the initial snap because no matching `.NET <Razor.RazorMajorVersion>.0.<Band>xx SDK` channel existed on `main` at the time, re-check now:
 - Re-query darc default-channels for `main` (`darc get-default-channels --source-repo https://github.com/{owner}/{repo} --branch main`).
-- If a `.NET <Major>.0.<Band>xx SDK` channel matching the current `<RazorMajorVersion>` is now present on `main` and `<Band>` differs from the current `<RazorMinorVersion>` in `eng/Versions.props`, include the `<RazorMajorVersion>`/`<RazorMinorVersion>` edit in this same post-VS-snap follow-up PR (using the same edit pattern as Step 3.5 / 5b).
+- If a `.NET <Major>.0.<Band>xx SDK` channel matching the current `<RazorMajorVersion>` is now present on `main` and `<Band>` differs from the current `<RazorMinorVersion>` in `eng/Versions.props`, include the `<RazorMajorVersion>`/`<RazorMinorVersion>` edit in this same post-VS-snap follow-up PR (using the same edit pattern as Step 3.5).
 - If still no matching SDK channel exists on `main`, leave Razor unchanged -- the bump waits for the next opportunity (i.e., when the channel is added).
 
 Remind the user of the exact schedule-derived follow-up date when finishing the snap, and pick this step up when the user resumes this session.
@@ -744,7 +738,7 @@ After completing the snap, review whether any steps needed to be done differentl
 |---------|---------|---------|
 | Roslyn version | `Major.Minor.Patch` | `5.6.0` |
 | VS version (from roslyn) | `(Major+13).(Minor)` | `18.6` |
-| VS version (from razor RazorVsixVersionPrefix) | Same as RazorVsixVersionPrefix major.minor | `18.6` |
+| Razor VSIX/Addin version | Derived from `VsMajorVersion.VsMinorVersion` | `18.6` |
 | Razor SDK version | `<RazorMajorVersion>.<RazorMinorVersion>` from `eng/Versions.props` | `10.4` |
 | Razor SDK <-> .NET SDK channel | `Razor X.Y` <-> `.NET X.0.Yxx SDK` | `Razor 10.4` <-> `.NET 10.0.4xx SDK` |
 | Named branches | `main` → `release/insiders` → `release/stable` | cascade order |

diff --git a/src/roslyn/eng/Versions.props b/src/roslyn/eng/Versions.props
@@ -28,15 +28,29 @@
     <RazorAssemblyVersion>$(RazorMajorVersion).$(RazorMinorVersion).0.0</RazorAssemblyVersion>
   </PropertyGroup>
 
+  <!-- Visual Studio train version (used to version VS components that ship out-of-band from Roslyn/Razor) -->
+  <PropertyGroup>
+    <VsMajorVersion>$([MSBuild]::Add($(MajorVersion), 13))</VsMajorVersion>
+    <VsMinorVersion>$(MinorVersion)</VsMinorVersion>
+  </PropertyGroup>
+
   <!-- Razor tooling version -->
   <PropertyGroup>
-    <RazorVsixVersionPrefix>18.12.1</RazorVsixVersionPrefix>
-    <RazorAddinMajorVersion>18.12</RazorAddinMajorVersion>
+    <RazorVsixPatchVersion>1</RazorVsixPatchVersion>
+    <RazorVsixVersionPrefix>$(VsMajorVersion).$(VsMinorVersion).$(RazorVsixPatchVersion)</RazorVsixVersionPrefix>
+    <RazorAddinMajorVersion>$(VsMajorVersion).$(VsMinorVersion)</RazorAddinMajorVersion>
     <RazorAddinVersion>$(RazorAddinMajorVersion)</RazorAddinVersion>
     <RazorAddinVersion Condition="'$(OfficialBuildId)' != ''">$(RazorAddinVersion).$(OfficialBuildId)</RazorAddinVersion>
     <RazorAddinVersion Condition="'$(OfficialBuildId)' == ''">$(RazorAddinVersion).42424242.42</RazorAddinVersion>
   </PropertyGroup>
 
+  <!-- EditorConfig components version -->
+  <PropertyGroup>
+    <EditorConfigPatchVersion>0</EditorConfigPatchVersion>
+    <EditorConfigVersionPrefix>$(VsMajorVersion).$(VsMinorVersion).$(EditorConfigPatchVersion)</EditorConfigVersionPrefix>
+    <EditorConfigAssemblyVersion>$(VsMajorVersion).$(VsMinorVersion).0.0</EditorConfigAssemblyVersion>
+  </PropertyGroup>
+
   <!--
     The maintenance-packages dependency versions need to be conditionally selected:
     https://github.com/dotnet/sdk/issues/45155

diff --git a/src/roslyn/src/Compilers/Server/VBCSCompiler/VBCSCompiler.cs b/src/roslyn/src/Compilers/Server/VBCSCompiler/VBCSCompiler.cs
@@ -19,7 +19,10 @@ public static int Main(string[] args)
                 return CommonCompiler.Failed;
             }
 
-            using var logger = new CompilerServerLogger($"VBCSCompiler {Process.GetCurrentProcess().Id}", options.LogFilePath);
+            var identifier = $"VBCSCompiler {Process.GetCurrentProcess().Id}";
+            using var logger = options.LogFilePath is null
+                ? new CompilerServerLogger(identifier, StandardBuildEnvironment.Instance)
+                : new CompilerServerLogger(identifier, options.LogFilePath);
 
 #if BOOTSTRAP
             ExitingTraceListener.Install(logger);

diff --git a/src/roslyn/src/Compilers/Server/VBCSCompilerTests/VBCSCompilerServerTests.cs b/src/roslyn/src/Compilers/Server/VBCSCompilerTests/VBCSCompilerServerTests.cs
@@ -34,6 +34,65 @@ public void Dispose()
 
         public class StartupTests : VBCSCompilerServerTests
         {
+            [Theory]
+            [InlineData(false)]
+            [InlineData(true)]
+            public void LoggingFromEnvironment(bool logToDirectory)
+            {
+                var directory = TempRoot.CreateDirectory();
+                var logPath = logToDirectory ? directory.Path : Path.Combine(directory.Path, "server.log");
+
+                RunServerWithLogging(logPath);
+
+                var logFile = Assert.Single(Directory.GetFiles(directory.Path));
+                if (logToDirectory)
+                {
+                    Assert.StartsWith("server.", Path.GetFileName(logFile));
+                    Assert.EndsWith(".log", logFile);
+                }
+                else
+                {
+                    Assert.Equal(logPath, logFile);
+                }
+
+                var log = File.ReadAllText(logFile);
+                Assert.Contains("ID=VBCSCompiler ", log);
+                Assert.Contains("Keep alive timeout is: 1000 milliseconds.", log);
+            }
+
+            [Fact]
+            public void ExplicitLogFileOverridesEnvironment()
+            {
+                var directory = TempRoot.CreateDirectory();
+                var environmentLogPath = Path.Combine(directory.Path, "environment.log");
+                var explicitLogPath = Path.Combine(directory.Path, "explicit.log");
+
+                RunServerWithLogging(environmentLogPath, $@" -log:""{explicitLogPath}""");
+
+                Assert.False(File.Exists(environmentLogPath));
+                var log = File.ReadAllText(explicitLogPath);
+                Assert.Contains("ID=VBCSCompiler ", log);
+                Assert.Contains("Keep alive timeout is: 1000 milliseconds.", log);
+            }
+
+            private static void RunServerWithLogging(string environmentLogPath, string additionalArguments = "")
+            {
+                var filePath = typeof(VBCSCompiler).Assembly.Location;
+                var arguments = $"-pipename:{ServerUtil.GetPipeName()} -timeout:1{additionalArguments}";
+                if (BuildServerConnection.IsBuiltinToolRunningOnCoreClr)
+                {
+                    arguments = RuntimeHostInfo.GetDotNetExecCommandLine(filePath, arguments);
+                    filePath = RuntimeHostInfo.GetDotNetHostPath(StandardBuildEnvironment.Instance);
+                }
+
+                var result = ProcessUtilities.Run(filePath, arguments, additionalEnvironmentVars:
+                    new Dictionary<string, string>
+                    {
+                        [CompilerServerLogger.EnvironmentVariableName] = environmentLogPath,
+                    });
+                Assert.True(result.ExitCode == CommonCompiler.Succeeded, result.ToString());
+            }
+
             [ConditionalFact(typeof(WindowsOnly))]
             [WorkItem(217709, "https://devdiv.visualstudio.com/DevDiv/_workitems/edit/217709")]
             public async Task ShadowCopyAnalyzerAssemblyLoaderMissingDirectory()

diff --git a/src/roslyn/src/LanguageServer/ProtocolUnitTests/References/FindAllReferencesHandlerTests.cs b/src/roslyn/src/LanguageServer/ProtocolUnitTests/References/FindAllReferencesHandlerTests.cs
@@ -12,11 +12,13 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.Host;
+using Microsoft.CodeAnalysis.Internal.Log;
 using Microsoft.CodeAnalysis.LanguageServer.Handler;
 using Microsoft.CodeAnalysis.ReferenceHighlighting;
 using Microsoft.CodeAnalysis.Test.Utilities;
 using Microsoft.CodeAnalysis.Testing;
 using Microsoft.CodeAnalysis.Text;
+using Microsoft.CodeAnalysis.UnitTests.Logging;
 using Roslyn.Test.Utilities;
 using Roslyn.Text.Adornments;
 using Roslyn.Utilities;
@@ -108,6 +110,36 @@ void M2()
         AssertHighlightCount(results, expectedDefinitionCount: 1, expectedWrittenReferenceCount: 0, expectedReferenceCount: 3);
     }
 
+    [Theory, CombinatorialData]
+    public async Task StreamedReferencesWithResultsAreNotReportedAsEmpty(bool mutatingLspWorkspace)
+    {
+        var markup =
+            """
+            class C
+            {
+                void M()
+                {
+                    {|caret:|}M();
+                }
+            }
+            """;
+        await using var testLspServer = await CreateTestLspServerAsync(markup, mutatingLspWorkspace, CapabilitiesWithVSExtensions);
+        using var progress = BufferedProgress.Create<object>(null);
+        using var telemetry = RoslynTelemetry.SetCurrent(new RoslynTelemetry());
+        var sink = new TestTelemetryEventSink();
+        using var registration = RoslynTelemetry.Current.AddEventSink(sink);
+
+        var results = await RunFindAllReferencesAsync(
+            testLspServer,
+            testLspServer.GetLocations("caret").Single(),
+            progress);
+
+        Assert.NotEmpty(results);
+        Assert.DoesNotContain(
+            sink.PostedEvents,
+            telemetryEvent => telemetryEvent.Name == "vs/ide/vbcs/lsp/symbolrequest/emptyresult");
+    }
+
     [Theory, CombinatorialData]
     public async Task TestFindAllReferencesAsync_Class(bool mutatingLspWorkspace)
     {