How to use Unknown to debug tinygrad with Deebo

The developers stress-tested Deebo against a real tinygrad debugging task, test_failure_53, associated with a $100 bounty. The failure lay inside the Linearizer optimizer, and the post says earlier attempts had not established a clear root cause.

Deebo first parsed the test and repository structure. It hypothesized that GROUPTOP optimization on uchar reductions was involved, then explored type promotion problems, stride edge cases, and scope conflicts. The reported solution path was to disable GROUPTOP in unsafe contexts or introduce explicit type coercion. The test passed, although the fix was still under review when the author posted.

The surrounding architecture explains how Deebo investigates problems. A mother agent starts scenario subprocesses, each testing a different hypothesis in its own Git branch. Those subprocesses use git-mcp and desktopCommander to validate or falsify candidate fixes. Results return asynchronously, and structured reasoning loops guide convergence. The post attributes the investigation to Deebo itself, but does not establish that the proposed fix was accepted upstream or identify which of the two described approaches was ultimately selected.

Who it's for: Developers investigating difficult optimizer failures who can evaluate experimental fixes before accepting them.

Prompt
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Source: Hacker News · finally4444