[Bug] Tool returns "Cannot read properties of undefined (reading 'prepare')" on web_search/fetch

[xueyingfeiwu]

When web_search_pro / web_fetch_pro tools execute and return results,
the parent process crashes with:

Cannot read properties of undefined (reading 'prepare')

DSH version: 0.1.0-rc.6
Platform: Windows 10/11
Affected tools: web_search_pro, web_fetch_pro, ask_user_question

Error is intermittent - sometimes retrying works.

[zoahdev]

This is the same family as #1697 (verified root cause + staged fix there): Cannot read properties of undefined (reading 'prepare') happens when two physical copies of @deepseek-ai/dsh-tools are loaded in one process. A profile-installed plugin's hoisted copy shadows the host copy; dsh-agent-loop reads ctx.tools[TOOL_RUNTIME_SCHEDULER] with the host copy's unique Symbol, while the ToolRuntime was stored under the shadowed copy's symbol → undefined.prepare(...).

Why it's intermittent on your setup: the lookup only crashes when the tool that triggered the turn went through the scheduler slot of the other instance. Retrying can land on a path that resolves the host copy, so it "sometimes works".

Quick checks:

1. Does your profile have a real-directory @deepseek-ai/* copy at the top level? Run:
   npx dsh-plugin-doctor --profile ~/.dsh/profiles/web (or node lib/bin.js --profile ... from https://github.com/zoahdev/dsh-plugin-doctor) — it flags exactly this precondition.
2. Workaround that unblocks immediately: add a link: dependency in the profile's package.json pointing at the host copy of @deepseek-ai/dsh-tools, then pnpm install in the profile (details in Bug: installing any plugin that depends on @deepseek-ai/dsh-tools breaks every tool call (Cannot read properties of undefined (reading 'prepare')) #1697).

Staged upstream fix (when PRs open): Symbol.for + TOOL_RUNTIME_SCHEDULER_PROTOCOL_VERSION guard on my fork branch: https://github.com/zoahdev/deepseek-harness/tree/fix/tool-runtime-scheduler-symbol-for