Microsoft.Testing.Extensions.CodeCoverage does not support MSBuild isolation

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#205 opened on Jan 23, 2026 0 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty: 4/5
Estimated time: 3-5 days
Newbie friendliness: 35/100

Issue type: Bug
Clarity: Mostly clear
Activity status: Stale
Tech stack: csharp
Domain: build-system

Research direction

Start with the Microsoft.Testing.Extensions.CodeCoverage.targets path shown in the error and read the linked MSBuild static-graph specification, especially its examples. Reproduce an MTP build using /isolate and determine what support is missing for the InitializeSourceRootMappedPaths target. Done means the isolated build no longer reports MSB4252.

Written by the indexing model from the issue text.

Description

When building a MTP project with /isolate we are observing this issue:

C:\Users\X\.nuget\packages\microsoft.testing.extensions.codecoverage\18.1.0\buildMultiTargeting\Microsoft.Testing.Extensions.CodeCoverage.targets(18,5): error 
      MSB4252: Project "C:\src\Foo.csproj" with global properties
          (NuGetInteractive=true; IsGraphBuild=true)
          is building project "C:\src\Bar.csproj" with global properties
          (NuGetInteractive=true; IsGraphBuild=true)
          with the (InitializeSourceRootMappedPaths) target(s) but the build result for the built project is not in the engine cache. In isolated builds this could mean one of the following:
          - the reference was called with a target which is not specified in the ProjectReferenceTargets item in project "C:\src\Foo.csproj"
          - the reference was called with global properties that do not match the static graph inferred nodes
          - the reference was not explicitly specified as a ProjectReference item in project "C:\src\Foo.csproj"

https://github.com/dotnet/msbuild/blob/main/documentation/specs/static-graph.md#examples is missing instructions for SDK owners.

Dominant language: C#
Stars: 125
Forks: 17
Avg merge: 1h 17m
Merged PRs (30d): 2

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