[ci-fix] Needs review: Add RequiresProcessIsolation to ByRefLike/Validate.csproj for minifullaot (refs #128767)

[github-actions]

Workflow artifact: ci-fix
Artifact kind: help
Linked KBE: #128767

Note

This is an AI/Copilot-generated best-effort fix attempt that I could not fully validate. It is a starting point for a maintainer, not a finished change. Please review the analysis below before merging.

Root cause (best analysis)

The ByRefLike/Validate.csproj test project has MonoAotIncompatible=true, which should exclude it from the minifullaot build via DisableProjectBuild. However, without RequiresProcessIsolation=true, the merged test runner assembly includes Validate.cs and GenericTypeSubstitution.cs as source files. The merged runner does NOT include the InvalidCSharp.ilproj ProjectReference (which IS properly excluded by DisableProjectBuild), resulting in:

error CS0246: The type or namespace name 'InvalidCSharp' could not be found

This error occurs in "Building managed test group 3" of the minifullaot build.

Attempted fix

Added <RequiresProcessIsolation>true</RequiresProcessIsolation> to Validate.csproj. This ensures the project is built as a standalone test (not merged into a group runner), so DisableProjectBuild properly excludes it from the minifullaot build.

This matches the exact pattern of the sibling ValidateNegative.csproj which already has:

<MonoAotIncompatible>true</MonoAotIncompatible>
<!-- Needed for MonoAotIncompatible, NativeAotIncompatible, CrossGenTest -->
<RequiresProcessIsolation>true</RequiresProcessIsolation>

What is unverified / where I need help

• Could not build-validate because the environment lacks the .NET 11 preview SDK required by this repo
• The fix is a 2-line .csproj property addition matching an existing sibling pattern — a quick local src/tests/build.sh -mono /p:RuntimeVariant=minifullaot on the Loader/classloader subtree would confirm

Validation

• Command: src/tests/build.sh ci os linux x64 Release -mono /p:RuntimeVariant=minifullaot (builds test group 3 which includes this project)
• Result: not run because .NET 11 preview SDK unavailable in agent environment

Evidence

• Failing build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1447125
• First build it occurred: build 1433744, 2026-05-25 (computed within the scanned window; may not be the true origin)
• Suspected regressing change: none identified — likely a pre-existing latent issue exposed when the test was first included in a merged runner group

Help wanted

• Area owners (area-VM-meta-mono): @steveisok, @dotnet/runtime-infrastructure

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Filed by ci-failure-fix. Comment here or on the workflow file to suggest changes; ci-failure-scan-feedback reads in-scope feedback daily and opens (or updates) a PR with prompt edits.

Note

🔒 Integrity filter blocked 1 item

The following item was blocked because it doesn't meet the GitHub integrity level.

• [ci-scan] Test failure: CustomAttributeDecoderTests.TestCustomAttributeDecoderGenericUsingReflection on maccatalyst #128450 issue_read: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".

To allow these resources, lower min-integrity in your GitHub frontmatter:

tools:
  github:
    min-integrity: approved  # merged | approved | unapproved | none

Generated by CI Outer-Loop Failure Fixer · ● 41.2M · ◷

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