stackalloc expression without an initializer inside SkipLocalsInit may only be used in an unsafe context

[EgorBo]

see #127944 (comment)

Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1414260&view=logs&jobId=d9e636e2-6ba5-5eef-4de1-6da5e37f2f04
Build error leg or test failing:

Error Message

Fill the error message using step by step known issues guidance.

{
  "ErrorMessage": "stackalloc expression without an initializer inside SkipLocalsInit may only be used in an unsafe context",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

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[agocke]

That’s a PR, it needs to be fixed before merge.

Also, known build error is useless for actual compiler failures.

[EgorBo]

@agocke why did you close it, it's still there, isn't? My PR is failing in files I didn't touch, see CI in #127995

[EgorBo]

or is it because it's not rebased? 🤔 let me check

[EgorBo]

E.g. https://github.com/dotnet/runtime/blob/main/src/libraries/System.Security.Cryptography/src/System/Security/Cryptography/X25519DiffieHellmanCng.Windows.cs#L44

it doesn't have an unsafe context so presumably it should fail to compile (and it did in my PR's CI run)