Fix TerminalLogger assert failure for metaproj files and cached project eval ID by OvesN · Pull Request #13480 · dotnet/msbuild

OvesN · 2026-04-01T16:01:44Z

Context

These metaproj files are never evaluated — they have EvaluationId = -1. The TerminalLogger's Debug.Assert assumes every ProjectStarted has a prior ProjectEvaluationFinished, which fails for metaproj files and crashes the build.

Additionally, a pre-existing bug (#12953) causes real projects to lose their evaluation IDs when their ProjectInstance is cached (released from memory), and when BuildResult packets are sent from worker nodes to the central node without carrying the eval ID.

Changes Made

TerminalLogger metaproj fix:

TerminalLogger.cs: Assert "EvalProjectInfo should have been captured before ProjectStarted"); will not fail now for metaproj files

Evaluation ID fixes (adapted from PR #12946):

BuildRequestConfiguration.cs: Added _projectEvaluationId field that persists through caching + IPC serialization in both Translate() and TranslateForFutureUse()
NodeLoggingContext.cs: Use config.ProjectEvaluationId instead of config.Project.EvaluationId (which is inaccessible when cached)
BuildResult.cs: Added _evaluationId field with version 2 serialization
RequestBuilder.cs: Populate result.EvaluationId at success, exception, and abort paths
BuildManager.cs: Update config.ProjectEvaluationId from worker node results

Testing

Unit tests

BuildRequestConfiguration_Tests
BuildResult_Tests

Integration testing:

Verified by building Roslyn and Aspire with Debug bootstrap MSBuild with and without /mt.

Notes

The evaluation ID fixes are adapted from PR Fill holes in BuildEventContext construction and evaluation ID propagation #12946.

…crash

Copilot

Pull request overview

Fixes TerminalLogger crashes and restores correct evaluation ID propagation across caching and cross-node result transfers, improving BuildEventContext consistency in multi-node (/m, /mt) builds.

Changes:

Make TerminalLogger’s ProjectStarted debug assertion tolerant of non-evaluated .metaproj projects.
Persist and propagate project evaluation IDs through configuration caching, node logging, worker→central result transfer, and BuildResult serialization.
Add/adjust unit tests for BuildResult/configuration serialization of evaluation IDs.

Reviewed changes

Copilot reviewed 10 out of 11 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/Framework/FileUtilities.cs	Makes `.metaproj` detection helpers null-tolerant for broader call-site safety.
src/Build/Logging/TerminalLogger/TerminalLogger.cs	Avoids Debug.Assert failure for `.metaproj` projects that never emit evaluation events.
src/Build/BuildCheck/Infrastructure/BuildCheckBuildEventHandler.cs	Centralizes metaproject detection by using `FileUtilities.IsMetaprojectFilename`.
src/Build/BackEnd/Shared/BuildResult.cs	Adds versioned `_evaluationId` field to allow eval ID propagation via result serialization.
src/Build/BackEnd/Shared/BuildRequestConfiguration.cs	Persists evaluation ID independently of cached `ProjectInstance` accessibility and serializes it.
src/Build/BackEnd/Components/RequestBuilder/RequestBuilder.cs	Populates `BuildResult.EvaluationId` for success/abort/exception paths.
src/Build/BackEnd/Components/Logging/NodeLoggingContext.cs	Uses persisted `ProjectEvaluationId` instead of reading from a potentially cached project.
src/Build/BackEnd/BuildManager/BuildManager.cs	Updates configuration evaluation ID from worker node results when available.
src/Build.UnitTests/TerminalLogger_Tests.cs	Whitespace-only adjustments.
src/Build.UnitTests/BackEnd/BuildResult_Tests.cs	Adds test to validate translation preserves `EvaluationId`.
src/Build.UnitTests/BackEnd/BuildRequestConfiguration_Tests.cs	Adds tests for `ProjectEvaluationId` preservation (translation/clone/future-use path).

src/Build/BackEnd/Shared/BuildResult.cs

src/Build.UnitTests/BackEnd/BuildRequestConfiguration_Tests.cs

JanProvaznik · 2026-04-02T08:19:18Z

src/Build/BackEnd/Shared/BuildResult.cs

            }
+
+            // Starting version 2 the _evaluationId field is present.
+            if (_version >= 2)


why is this versioned?

It follows the existing pattern for _buildRequestDataFlag.

Should we be deprecating some of the older versions? That's what the comment suggests

https://github.com/OvesN/msbuild/blob/e8163763277f67f201dbe5553e5ee447f1a70718/src/Build/BackEnd/Shared/BuildResult.cs#L656-L668

@dfederm do you have a sense on BuildResult staleness here?

src/Build/Logging/TerminalLogger/TerminalLogger.cs

…crash

rainersigwald

#13489 should improve the test that flaked out on the current run. I'm not rerunning because I'm not convinced this is the right solution to the problem thouh.

rainersigwald · 2026-04-06T15:13:26Z

src/Build/Logging/TerminalLogger/TerminalLogger.cs

            }
-            System.Diagnostics.Debug.Assert(evalInfo != default, "EvalProjectInfo should have been captured before ProjectStarted");
+
+            // Metaproj files (generated for multi-targeting and solution builds) are never evaluated,


I don't think this is the right fix because metaproj files do evaluate and raise the ProjectEvaluationFinished event:

> Microsoft.Build.Framework.dll!Microsoft.Build.Framework.ProjectEvaluationFinishedEventArgs.ProjectEvaluationFinishedEventArgs(string message, object[] messageArgs) Line 27 C# Microsoft.Build.dll!Microsoft.Build.BackEnd.Logging.LoggingService.LogProjectEvaluationFinished(Microsoft.Build.Framework.BuildEventContext projectEvaluationEventContext, string projectFile, System.Collections.IEnumerable globalProperties, System.Collections.IEnumerable properties, System.Collections.IEnumerable items, Microsoft.Build.Framework.Profiler.ProfilerResult? profilerResult) Line 460 C# Microsoft.Build.dll!Microsoft.Build.BackEnd.Components.Logging.EvaluationLoggingContext.LogProjectEvaluationFinished(System.Collections.IEnumerable globalProperties, System.Collections.IEnumerable properties, System.Collections.IEnumerable items, Microsoft.Build.Framework.Profiler.ProfilerResult? profilerResult) Line 46 C# Microsoft.Build.dll!Microsoft.Build.Evaluation.Evaluator<Microsoft.Build.Execution.ProjectPropertyInstance, Microsoft.Build.Execution.ProjectItemInstance, Microsoft.Build.Execution.ProjectMetadataInstance, Microsoft.Build.Execution.ProjectItemDefinitionInstance>.Evaluate(Microsoft.Build.Evaluation.IEvaluatorData<Microsoft.Build.Execution.ProjectPropertyInstance, Microsoft.Build.Execution.ProjectItemInstance, Microsoft.Build.Execution.ProjectMetadataInstance, Microsoft.Build.Execution.ProjectItemDefinitionInstance> data, Microsoft.Build.Evaluation.Project project, Microsoft.Build.Construction.ProjectRootElement root, Microsoft.Build.Evaluation.ProjectLoadSettings loadSettings, int maxNodeCount, Microsoft.Build.Collections.PropertyDictionary<Microsoft.Build.Execution.ProjectPropertyInstance> environmentProperties, System.Collections.Generic.ICollection<string> propertiesFromCommandLine, Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Evaluation.IItemFactory<Microsoft.Build.Execution.ProjectItemInstance, Microsoft.Build.Execution.ProjectItemInstance> itemFactory, Microsoft.Build.Evaluation.IToolsetProvider toolsetProvider, Microsoft.Build.FileSystem.IDirectoryCacheFactory directoryCacheFactory, Microsoft.Build.Evaluation.ProjectRootElementCacheBase projectRootElementCache, Microsoft.Build.Framework.BuildEventContext buildEventContext, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, int submissionId, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext, bool interactive) Line 366 C# Microsoft.Build.dll!Microsoft.Build.Execution.ProjectInstance.Initialize(Microsoft.Build.Construction.ProjectRootElement xml, System.Collections.Generic.IDictionary<string, string> globalProperties, string explicitToolsVersion, string explicitSubToolsetVersion, int visualStudioVersionFromSolution, Microsoft.Build.Execution.BuildParameters buildParameters, Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Framework.BuildEventContext buildEventContext, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, int submissionId, Microsoft.Build.Evaluation.ProjectLoadSettings? projectLoadSettings, Microsoft.Build.Evaluation.Context.EvaluationContext evaluationContext, Microsoft.Build.FileSystem.IDirectoryCacheFactory directoryCacheFactory) Line 3275 C# Microsoft.Build.dll!Microsoft.Build.Execution.ProjectInstance.ProjectInstance(Microsoft.Build.Construction.ProjectRootElement xml, System.Collections.Generic.IDictionary<string, string> globalProperties, string toolsVersion, Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, int visualStudioVersionFromSolution, Microsoft.Build.Evaluation.ProjectCollection projectCollection, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, int submissionId) Line 637 C# Microsoft.Build.dll!Microsoft.Build.Construction.SolutionProjectGenerator.CreateTraversalInstance(string wrapperProjectToolsVersion, bool explicitToolsVersionSpecified, System.Collections.Generic.List<Microsoft.Build.Construction.ProjectInSolution> projectsInOrder) Line 990 C# Microsoft.Build.dll!Microsoft.Build.Construction.SolutionProjectGenerator.CreateSolutionProject(string wrapperProjectToolsVersion, bool explicitToolsVersionSpecified) Line 750 C# Microsoft.Build.dll!Microsoft.Build.Construction.SolutionProjectGenerator.Generate() Line 712 C# Microsoft.Build.dll!Microsoft.Build.Construction.SolutionProjectGenerator.Generate(Microsoft.Build.Construction.SolutionFile solution, System.Collections.Generic.IDictionary<string, string> globalProperties, string toolsVersionOverride, Microsoft.Build.Framework.BuildEventContext projectBuildEventContext, Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, System.Collections.Generic.IReadOnlyCollection<string> targetNames, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, int submissionId) Line 229 C# Microsoft.Build.dll!Microsoft.Build.Execution.ProjectInstance.GenerateSolutionWrapper(string projectFile, System.Collections.Generic.IDictionary<string, string> globalProperties, string toolsVersion, Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Framework.BuildEventContext projectBuildEventContext, System.Collections.Generic.IReadOnlyCollection<string> targetNames, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, int submissionId) Line 3003 C# Microsoft.Build.dll!Microsoft.Build.Execution.ProjectInstance.CalculateToolsVersionAndGenerateSolutionWrapper(string projectFile, Microsoft.Build.Execution.BuildParameters buildParameters, Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Framework.BuildEventContext projectBuildEventContext, System.Collections.Generic.Dictionary<string, string> globalProperties, bool isExplicitlyLoaded, System.Collections.Generic.IReadOnlyCollection<string> targetNames, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, int submissionId) Line 2707 C# Microsoft.Build.dll!Microsoft.Build.Execution.ProjectInstance.LoadSolutionForBuild(string projectFile, Microsoft.Build.Collections.PropertyDictionary<Microsoft.Build.Execution.ProjectPropertyInstance> globalPropertiesInstances, string toolsVersion, Microsoft.Build.Execution.BuildParameters buildParameters, Microsoft.Build.BackEnd.Logging.ILoggingService loggingService, Microsoft.Build.Framework.BuildEventContext projectBuildEventContext, bool isExplicitlyLoaded, System.Collections.Generic.IReadOnlyCollection<string> targetNames, Microsoft.Build.BackEnd.SdkResolution.ISdkResolverService sdkResolverService, int submissionId) Line 2671 C# Microsoft.Build.dll!Microsoft.Build.Execution.BuildManager.LoadSolutionIntoConfiguration(Microsoft.Build.BackEnd.BuildRequestConfiguration config, Microsoft.Build.BackEnd.BuildRequest request) Line 1738 C# Microsoft.Build.dll!Microsoft.Build.Execution.BuildManager.HandleNewRequest(int node, Microsoft.Build.BackEnd.BuildRequestBlocker blocker) Line 2607 C#

The comment I wrote about all metaproj files never being evaluated was wrong. There are actually two kinds of
metaproj files, and one of them is evaluated.

The solution metaproj (.sln.metaproj) is evaluated and has a valid evaluation ID, so the assertion passes.

Per-project metaprojs (.csproj.metaproj, .vbproj.metaproj) are not evaluated and they fail the assertion.

I've fixed the comment

rainersigwald · 2026-04-06T15:20:23Z

src/Build/BackEnd/Shared/BuildResult.cs

            }
+
+            // Starting version 2 the _evaluationId field is present.
+            if (_version >= 2)


Should we be deprecating some of the older versions? That's what the comment suggests

https://github.com/OvesN/msbuild/blob/e8163763277f67f201dbe5553e5ee447f1a70718/src/Build/BackEnd/Shared/BuildResult.cs#L656-L668

@dfederm do you have a sense on BuildResult staleness here?

OvesN and others added 7 commits April 1, 2026 17:54

fix terminal logger id crash

d9bc8f7

ignore metaproj while assertion

ee460ce

better metaproj check

494c003

tests + cleaner metaproject file detection

0f743d4

Merge branch 'main' into dev/veronikao/fix-TL-eval-before-proj-start-…

0b77d8f

…crash

Delete unnecessary tests,

70c0f1a

cleanup

e816376

OvesN self-assigned this Apr 2, 2026

OvesN marked this pull request as ready for review April 2, 2026 08:00

Copilot AI review requested due to automatic review settings April 2, 2026 08:00

Copilot started reviewing on behalf of OvesN April 2, 2026 08:01 View session

Copilot AI reviewed Apr 2, 2026

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src/Build/BackEnd/Shared/BuildResult.cs Show resolved Hide resolved

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JanProvaznik approved these changes Apr 2, 2026

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OvesN requested a review from SimaTian April 2, 2026 10:42

SimaTian approved these changes Apr 2, 2026

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OvesN and others added 2 commits April 2, 2026 17:57

Add new test for assert, fix test.

0072052

Merge branch 'main' into dev/veronikao/fix-TL-eval-before-proj-start-…

95f1de6

…crash

OvesN enabled auto-merge (squash) April 2, 2026 15:57

rainersigwald reviewed Apr 6, 2026

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Fix comment

ee9daa3

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Fix TerminalLogger assert failure for metaproj files and cached project eval ID#13480

Fix TerminalLogger assert failure for metaproj files and cached project eval ID#13480
OvesN wants to merge 10 commits intodotnet:mainfrom
OvesN:dev/veronikao/fix-TL-eval-before-proj-start-crash

OvesN commented Apr 1, 2026 •

edited

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OvesN commented Apr 1, 2026 •

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