[crac] RFR: 8364538: [CRaC] Test CRaCIgnoreRestoreIfUnavailable [v2]

[Radim Vansa]

On Tue, 5 Aug 2025 07:09:45 GMT, Timofei Pushkin <tpushkin at openjdk.org> wrote:

>> Yes, if there are no CPU features — that is a different failure.
>> 
>> Did not want to add a test for that because I am not testing CPU features in this PR, but this particular one should not be hard to implement so I'll add it.
>
> Added  `NoCPUFeaturesTest`

I was not implying that you should add the test for missing CPU features, but good to have one.

My point is that running `simengine` alone should be a no-op (yes, you're testing that simengine works, but that's not a point of this test). The comment says `Create an empty image` but simengine is not supposed to create an empty image, it is not supposed to do anything. As a side-effect, JVM creates the directory.

My understanding is that you are doing that to prevent checks before entering the engine to fail in a different manner than the test is supposed to do. I consider running the test with two different engines a confusing, obscure way to get the prerequisites; you could just `mkdir` and write a dummy CPU features file.

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PR Review Comment: https://git.openjdk.org/crac/pull/255#discussion_r2254234508