AccessViolationException accessing Commit.Parents concurrently on Linux .NET 10

Environment

• LibGit2Sharp 0.32.0
• LibGit2Sharp.NativeBinaries 2.0.324 (libgit2 1.8.6)
• .NET SDK/runtime 10.0.400
• Linux x64, GitHub-hosted Ubuntu 24.04 runner

Failure

A test process intermittently terminates with System.AccessViolationException while accessing Commit.Parents during a version-height calculation. The test uses distinct temporary repositories per test instance, and the LibGit2Context and its Repository are both live and strongly referenced throughout the failing call.

The latest occurrence is in this public GitHub Actions job:
https://github.com/dotnet/Nerdbank.GitVersioning/actions/runs/33464845055/job/99722455984

Relevant managed stack:

System.AccessViolationException: Attempted to read or write protected memory.
   at Nerdbank.GitVersioning.LibGit2.LibGit2GitExtensions.<GetCommitHeight>g__TryCalculateHeight|19_0(LibGit2Sharp.Commit, <>c__DisplayClass19_0 ByRef)
   at Nerdbank.GitVersioning.LibGit2.LibGit2GitExtensions.GetCommitHeight(LibGit2Sharp.Commit, GitWalkTracker, Func<Commit, Boolean>)
   at Nerdbank.GitVersioning.LibGit2.LibGit2GitExtensions.GetVersionHeight(LibGit2Context, Version)
   at Nerdbank.GitVersioning.LibGit2.LibGit2Context.CalculateVersionHeight(VersionOptions, VersionOptions)
   at Nerdbank.GitVersioning.VersionOracle..ctor(GitContext, ICloudBuild, Nullable<Int32>)
   at VersionOracleTests.CloudBuildNumber_4thPosition(...)

TryCalculateHeight is walking commit.Parents; this theory does not configure path filters, so it does not call Diff.Compare.

Investigation

We found and fixed separate repository-local lifetime defects where a lazy commit query escaped its context and a VersionOracle retained a disposed context. This crash persists after those fixes, and the present stack has no escaped lazy sequence or disposed native owner.

The test assembly's normal xUnit test-collection parallelism is the remaining variable. We are temporarily serializing test collections to prevent the intermittent native process crash, but would prefer a LibGit2Sharp/libgit2 fix or guidance about concurrent independent repository operations on Linux/.NET 10.

Related historical reports include #988 and #1513, but this report targets the current package versions and live-context Commit.Parents failure.

Comienza reproduciendo VersionOracleTests.CloudBuildNumber_4thPosition en el trabajo de Ubuntu 24.04 GitHub Actions enlazado y, después, inspecciona TryCalculateHeight, donde se accede a Commit.Parents de forma concurrente. Compara el comportamiento con las colecciones de pruebas serializadas temporalmente y determina si se admiten operaciones independientes del repositorio; se considera terminado cuando se documente la causa y se proporcione una corrección confirmada o una guía para las versiones actuales del paquete.