Fix FlashAttention 2 detection when only FlashAttention 4 is installed - #269
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lfengad merged 1 commit intoSep 22, 2026
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Signed-off-by: Rahul Steiger <rsteiger@nvidia.com>
lfengad
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Fixes a crash in
flash2_supported()when FlashAttention 4 provides theflash_attnnamespace but the FlashAttention 2 distribution is not installed. The metadata lookup previously raisedPackageNotFoundError, breaking Cosmos Framework imports.The check now returns
Falsewhen FA2 metadata is missing, allowing optional backend detection to continue.Validation: six tests pass, including a regression test confirmed to fail before the fix. Lint and formatting checks pass. The full GPU suite was not run.