electron-builder's `extraMetadata` feature mutates the source
package.json in place during packaging and restores it on clean
exit. When the builder is killed mid-flight (parent task timeout,
Ctrl-C, OOM) the restore never fires and the source tree is left
with a stripped scripts block — every subsequent pnpm command
then fails with "Missing script" until someone notices the drift
and runs `git checkout`. Observed once in this session when a
`build:dir` task was cancelled mid-packaging.
Wrap the builder invocation in a bytes-level snapshot + idempotent
restore, driven by both normal-exit and SIGINT/SIGTERM/SIGHUP
handlers. On a clean run the builder's own restore wrote the
original bytes back, our final compare is byte-equal, and the
restore is a no-op. On an abnormal termination the snapshot
overwrites whatever electron-builder left behind so the working
tree is guaranteed clean regardless of exit path.
The snapshot approach is intentional over a "reject if tree dirty
before build" guard: this is a recovery mechanism, not a
precondition, and the repo's own `package.json` is the truth —
anything else in there at the moment the builder took its snapshot
is the desired state.
ZacharyZhang-NY