Engine crash: serde_json serialization failed: key must be a string

[brockgerrard-cmd]

What happened
briefly describe what you were doing

Diagnostic

Build: v0.43.0 (96e41b3)
Diagnostic tag: submitAction-panic
Game id: f8d10cbf-a2f4-47bd-b1f8-916dca2a8df2
Game mode: ai
User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36 Edg/151.0.0.0

Panic:
panicked at crates/engine-wasm/src/lib.rs:115:29: serde_json serialization failed: key must be a string

[mike-theDude]

Triage analysis

Clarified summary

Submitting an action in an AI game panics while serializing the engine response for WASM: serde_json encounters a map key that cannot be represented as a JSON object key.

Investigation findings

The diagnostic includes build v0.43.0, game id, browser, panic site, and exact serialization error. The current WASM bridge serializes the response with serde_json::to_string; contrary to its broad comment, structured map-key types are not automatically valid JSON keys. The report does not include a saved state or action, so the offending response field still needs isolation. No exact duplicate was found.

Acceptance criteria

• Identify and serialize the non-string-keyed map through a stable JSON-compatible representation.
• submitAction returns a valid JS response for the reported state shape without panicking.
• Round-trip tests cover the offending key type and preserve frontend lookup semantics.
• Serialization failure, if ever encountered, is surfaced without destroying the game session.

Related issues

No exact duplicate found.

[mike-theDude]

Classifier analysis

Verdict: not_card_data
Matched clause: None (supported: not applicable)
Reasoning: This is a WASM/JSON transport serialization panic involving a Rust map key, independent of Oracle parsing.

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Posted by bug-coverage-classifier skill.