# `PtcRunner.Lisp.ExecutionError`
[🔗](https://github.com/andreasronge/ptc_runner/blob/main/lib/ptc_runner/lisp/execution_error.ex#L1)

Exception used to signal execution errors during Lisp evaluation.

This exception is used internally by the `tool_executor` and `ToolNormalizer`
to propagate structured errors (like unknown tools or tool failures)
out of the evaluation loop and into the `Step` failure result.

# `stable_parallel_reasons`
*macro* 

Compile-time list of stable parallel error reasons that must survive
nesting unchanged so the security/capacity outcome is deterministic at
any depth. Safe to use in guard clauses.

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*Consult [api-reference.md](api-reference.md) for complete listing*