Missing operationId reults in cryptic error

[AI0867]

Running skiffa generator on an API specification that has a missing operationId somewhere, results in the following error, which isn't very informative.

RuntimeError: unreachable
    at skiffa_core.wasm (wasm://wasm/skiffa_core.wasm-0071e42a:wasm-function[2330]:0x1582b6)
    at skiffa_core.wasm (wasm://wasm/skiffa_core.wasm-0071e42a:wasm-function[2167]:0x157b96)
    at skiffa_core.wasm (wasm://wasm/skiffa_core.wasm-0071e42a:wasm-function[1194]:0x140c08)
    at skiffa_core.wasm (wasm://wasm/skiffa_core.wasm-0071e42a:wasm-function[1388]:0x14a230)
    at skiffa_core.wasm (wasm://wasm/skiffa_core.wasm-0071e42a:wasm-function[2279]:0x158135)
    at skiffa_core.wasm (wasm://wasm/skiffa_core.wasm-0071e42a:wasm-function[1757]:0x153757)
    at skiffa_core.wasm (wasm://wasm/skiffa_core.wasm-0071e42a:wasm-function[1802]:0x15423f)
    at skiffa_core.wasm (wasm://wasm/skiffa_core.wasm-0071e42a:wasm-function[1752]:0x153613)
    at skiffa_core.wasm (wasm://wasm/skiffa_core.wasm-0071e42a:wasm-function[2173]:0x157bec)
    at skiffa_core.wasm (wasm://wasm/skiffa_core.wasm-0071e42a:wasm-function[75]:0x5ff3a)