{"record":{"id":"e7674ecaea7bd63a","repo":"JuliusBrussee/caveman","slug":"where-representative-trace-trace-analysis-uni-e7674e","errorCode":null,"errorMessage":"${where} representative trace ${trace.analysis_unit_id} did not run that arm's workflow variant","messagePattern":"(.+?) representative trace (.+?) did not run that arm's workflow variant","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"packages/shared/contracts/scripts/validate-continuous-improvement.mjs","lineNumber":164,"sourceCode":"    for (const arm of item.cohort.arms) {\n      const variant = variantsByID.get(arm.variant_id);\n      if (!variant) throw new Error(`${where} cohort arm ${arm.role} references a workflow variant that is not in this report`);\n      if (variant.task_family_id !== family.id) throw new Error(`${where} cohort arm ${arm.role} uses a variant of another task family`);\n      armVariants.set(arm.role, variant);\n      comparedUnits += arm.unit_count;\n    }\n    const excluded = item.cohort.excluded_units.reduce((total, exclusion) => total + exclusion.unit_count, 0);\n    if (comparedUnits + excluded !== item.cohort.family_unit_count) {\n      throw new Error(`${where} cohort arms (${comparedUnits}) plus exclusions (${excluded}) do not account for its ${item.cohort.family_unit_count} family units`);\n    }\n\n    const selectedPerArm = new Map();\n    for (const trace of item.representative_traces) {\n      const variant = armVariants.get(trace.arm);\n      if (!variant || variant.id !== trace.variant_id) throw new Error(`${where} representative trace names a variant that is not that arm's variant`);\n      if (!unitsByID.has(trace.analysis_unit_id)) throw new Error(`${where} representative trace ${trace.analysis_unit_id} is not an analysis unit of this report`);\n      if (!familyUnits.has(trace.analysis_unit_id)) throw new Error(`${where} representative trace ${trace.analysis_unit_id} is not a member of the cohort's task family`);\n      if (!variant.analysis_unit_ids.includes(trace.analysis_unit_id)) throw new Error(`${where} representative trace ${trace.analysis_unit_id} did not run that arm's workflow variant`);\n      selectedPerArm.set(trace.arm, (selectedPerArm.get(trace.arm) ?? 0) + 1);\n    }\n    for (const [arm, count] of selectedPerArm) {\n      if (count > 3) throw new Error(`${where} arm ${arm} carries ${count} representative traces, more than three`);\n    }\n\n    const slice = item.causal_slice;\n    const sliceVariant = variantsByID.get(slice.variant_id);\n    if (!sliceVariant) throw new Error(`${where} causal slice references a workflow variant that is not in this report`);\n    if (sliceVariant.id !== armVariants.get(\"baseline\").id) throw new Error(`${where} causal slice is not taken from the baseline arm's variant`);\n    const sliceNodes = new Set(sliceVariant.nodes.map((node) => node.id));\n    if (slice.manifestation_node_id !== \"\" && !sliceNodes.has(slice.manifestation_node_id)) {\n      throw new Error(`${where} manifestation node ${slice.manifestation_node_id} is not a node of variant ${sliceVariant.id}`);\n    }\n    if (item.diagnosis.manifestation.node_id !== slice.manifestation_node_id) {\n      throw new Error(`${where} diagnosis manifestation node disagrees with its causal slice`);\n    }\n    for (const nodeID of slice.node_chain) {","sourceCodeStart":146,"sourceCodeEnd":182,"githubUrl":"https://github.com/JuliusBrussee/caveman/blob/766dce6b1394ebb56a3090748d5a0240a5aefb36/packages/shared/contracts/scripts/validate-continuous-improvement.mjs#L146-L182","documentation":"The strongest of the three trace checks: the unit must be listed in the arm variant's own analysis_unit_ids — the recorded run must actually have executed that arm's workflow variant (validate-continuous-improvement.mjs:164). Family membership alone is not enough: within one family different units ran different variants, and a representative trace must come from one that ran this arm's variant.","triggerScenarios":"The trace cites a unit that ran the alternative variant but is filed under the baseline arm; variant.analysis_unit_ids is stale after runs were re-attributed between variants of the same family; a trace copied between arms of a cohort whose variants share a family.","commonSituations":"Two variants of one family with overlapping unit pools; re-attributing runs between variants in the generator without refreshing traces; hand-picking an interesting unit without checking which variant executed it.","solutions":["Pick a trace unit that appears in the arm variant's analysis_unit_ids.","If the attribution is wrong, fix variant.analysis_unit_ids so it lists the units that actually ran it.","Re-run the validator; errors 609 and 610 for the same trace are fixed by the same edit."],"exampleFix":"// before — unit-code-7 is in wf-build-02's analysis_unit_ids, not wf-build-01's\n{ \"arm\": \"baseline\", \"variant_id\": \"wf-build-01\", \"analysis_unit_id\": \"unit-code-7\" }\n// after\n{ \"arm\": \"baseline\", \"variant_id\": \"wf-build-01\", \"analysis_unit_id\": \"unit-code-1\" }","handlingStrategy":"validation","validationCode":"const tracesOutsideArmVariant = (report) => {\n  const byID = new Map(report.workflow_variants.map((v) => [v.id, v]));\n  return report.cases.flatMap((c) => {\n    const armVariant = new Map(c.cohort.arms.map((a) => [a.role, byID.get(a.variant_id)]));\n    return c.representative_traces\n      .filter((t) => !armVariant.get(t.arm)?.analysis_unit_ids.includes(t.analysis_unit_id))\n      .map((t) => `${c.id}:${t.analysis_unit_id}`);\n  });\n};","typeGuard":null,"tryCatchPattern":"try {\n  execFileSync(process.execPath, [VALIDATOR, reportPath, spansPath]);\n} catch (err) {\n  if (/did not run that arm's workflow variant/.test(err.message)) {\n    failCI(`trace unit ran a different variant of the family: ${err.message}`);\n  } else throw err;\n}","preventionTips":["Pick each trace from the arm variant's own analysis_unit_ids list.","When re-attributing runs between variants, refresh every trace citing those units.","Check arm/variant consistency (error 608) first — it changes which list applies."],"tags":["fixtures","cross-validation","representative-trace","variant","membership"],"backgroundTag":"membership-violation","analyzedSha":"766dce6b1394ebb56a3090748d5a0240a5aefb36","analyzedAt":"2026-08-18T03:14:35.516Z","contentChangedAt":"2026-08-18T03:14:35.516Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}