[Desktop] PTC run_code fails immediately with worker-exit …before completing (0) after the host moved to the ASAR runtime

[ajia1206]

Summary

On a packaged Desktop build (0.1.6-alpha.1), every run_code call in the ptc preset fails immediately with:

Error: code run failed (worker-exit): Node process exited before completing (0)

The call fails in well under a second with empty stdout/stderr, so no tool can be used in PTC sessions. Restarting the application does not help.

Environment

• DeepSeek Harness Desktop 0.1.6-alpha.1, packaged build, macOS (arm64)
• dsh 0.1.6-alpha.1, agent preset ptc, file policy danger-full-access
• First observed after the application was updated to a build that contains feat(desktop): run runtime host from asar

Cause

Three facts combine:

1. For packaged builds apps/desktop/src/main.ts uses process.execPath as the Host executable, and apps/desktop/src/host-process.ts launches it with ELECTRON_RUN_AS_NODE=1. Inside that Host, process.execPath is therefore the Electron application binary.
2. packages/ptc-runtime/ptc-runtime-node/src/index.ts resolves its default worker executable from process.execPath and builds the worker environment by clearing inherited names, which removes ELECTRON_RUN_AS_NODE.
3. The worker spawn therefore boots the desktop application again instead of a Node process. The already-running application owns the single-instance lock, so the new process quits with exit code 0 and no output, which the runtime reports as worker-exit.

Local verification supporting the cause:

• While the application is running, spawning the application binary with the worker argv and without ELECTRON_RUN_AS_NODE exits with code 0 in under a second with empty stdout and stderr — exactly the reported failure.
• The same command with ELECTRON_RUN_AS_NODE=1 boots the worker (it reaches the control-channel handshake), so the worker itself is fine.

Suggested fix

Keep the worker in Node mode when the resolved executable is the current Electron binary, next to the existing executable/bootstrap selection:

export function nodeModeEnvironment(executable: string, hostExecutable: string, electron: boolean): Record<string, string> {
  if (!electron || executable !== hostExecutable) return {}
  return { ELECTRON_RUN_AS_NODE: '1' }
}

and merge it into the worker environment in run(). Local verification after this change: an end-to-end PTC run against a packaged build returns the program result, the package suite passes on plain Node, and it passes under an Electron-as-node Host except for one fixture whose program spawns process.execPath itself (that case still starts the application, because the program-visible environment is empty by design).

[ajia1206]

The patch for this report is available on a fork, because pull requests are disabled for this repository:

• Branch: https://github.com/ajia1206/deepseek-harness/tree/codex/ptc-electron-node-mode
• Commit: ajia1206@1ac395e

Contents:

• packages/ptc-runtime/ptc-runtime-node/src/launch.ts — adds nodeModeEnvironment, which returns ELECTRON_RUN_AS_NODE=1 when the resolved worker executable is the current Electron binary.
• packages/ptc-runtime/ptc-runtime-node/src/index.ts — merges that entry into the worker environment after the ambient scrub.
• Tests for the helper, the spawn environment under an Electron host and a plain Node host, and the direct worker boot.
• README.{md,zh.md} plus an Agent Note under .agents/notes/implemented/bug-fix/2026-09-15-electron-host-node-worker.*.

Evidence:

pnpm vitest run packages/ptc-runtime/ptc-runtime-node          # 12 files, 188 passed | 1 skipped (plain Node host)
same suite under the application binary + ELECTRON_RUN_AS_NODE=1 # 187 passed | 1 skipped (real worker spawns)
pnpm run test:docs                                              # 20 passed, 0 failed, 0 skipped

End-to-end against a packaged build: before the change the worker spawn exits with code 0 in under a second with empty stdout/stderr; with the entry supplied, a full PTC run returns its program result. The one remaining failure under an Electron-as-node host is the fixture whose program spawns process.execPath itself, which starts the application because the program-visible environment is empty by design.