Beagle SCM

JS-112: require() keeps a module cached after its evaluation throws

Proposed by the 2026-07-07 jab multi-agent review; confirmed by both skeptic verifiers. Node's CommonJS contract removes a module from the cache when its evaluation throws, so a retry re-evaluates; jab instead returns the half-initialized exports silently.

Input

Context

• cache[abs] = module; // before eval: cycle-safe (jab require.cpp:76) then fn(module, ...) (require.cpp:78-80) with no try/catch removing the entry on failure.
• try { require('./a.js') } catch (e) {} ... require('./a.js') — the second call hits the cache (require.cpp:73) and returns partial exports, hiding the original failure.
• test/require.js does not cover a throwing module.

Goals

• Repro first: throwing module, second require re-evaluates (Node semantics).
• try/catch around the eval; delete cache[abs] before rethrowing; cycle-safety preserved.

Constraints

• Keep the before-eval cache insert (cycles); only the failure path changes.

WIP

TODOs

• repro in test/require.js
• delete-on-throw in the require machine