{"record":{"id":"6839cdac1ac0842a","repo":"deepseek-ai/deepseek-harness","slug":"agent-presets-preset-presetid-failed-to-moun-6839cd","errorCode":null,"errorMessage":"agent-presets: preset \"${presetId}\" failed to mount: ${mountDetail(error)} (${preset.path})","messagePattern":"agent-presets: preset \"(.+?)\" failed to mount: (.+?) \\((.+?)\\)","errorType":"exception","errorClass":"PresetMountError","httpStatus":null,"severity":"error","filePath":"packages/preset/agent-presets/src/mount.ts","lineNumber":379,"sourceCode":"    const leaked = leakedServices(agentCtx, fiber)\n    if (leaked.length > 0) {\n      throw new Error(\n        `row(s) published process-global service(s) [${leaked.join(', ')}]; `\n        + 'a preset service must sit behind an `isolate` realm or move to the host composition',\n      )\n    }\n    mounts.add({ presetId: preset.id, fiber, key: scopeOf(agentCtx) })\n  } catch (error) {\n    try {\n      await handle.dispose()\n    /* v8 ignore next 5 -- teardown of a subtree nothing else references has no\n       observed failure mode; the guard exists so a teardown error cannot\n       replace the mount diagnostic the caller needs. */\n    } catch {\n      // Swallows only this subtree's teardown failure. The mount error below is\n      // the actionable one, and the discarded fiber is unreachable either way.\n    }\n    throw new PresetMountError(preset.id, `${mountDetail(error)} (${preset.path})`, { cause: error })\n  }\n}\n","sourceCodeStart":361,"sourceCodeEnd":382,"githubUrl":"https://github.com/deepseek-ai/deepseek-harness/blob/b150a551b8d465e31e418e1b2eaf5e79bbb7d28e/packages/preset/agent-presets/src/mount.ts#L361-L382","documentation":"Error \"agent-presets: preset \"${presetId}\" failed to mount: ${mountDetail(error)} (${preset.path})\" thrown in deepseek-ai/deepseek-harness.","triggerScenarios":"Thrown at packages/preset/agent-presets/src/mount.ts:379 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Fix the preset per the included mount detail, then mount again."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"b150a551b8d465e31e418e1b2eaf5e79bbb7d28e","analyzedAt":"2026-08-24T18:12:29.105Z","schemaVersion":2},"datasetVersion":"2026-08-24T22:17:12.610Z"}