{"record":{"id":"86d3bb1ce502d6df","repo":"JuliusBrussee/caveman","slug":"assembly-slot-slot-id-r-changed-after-being-decl","errorCode":null,"errorMessage":"assembly slot {slot_id!r} changed after being declared stable","messagePattern":"assembly slot (.+?) changed after being declared stable","errorType":"validation","errorClass":"AssemblyStabilityError","httpStatus":null,"severity":"error","filePath":"packages/sdk/python/caveman_cloud/core.py","lineNumber":443,"sourceCode":"            ids.add(slot.id)\n            if slot.stability not in {\"stable\", \"session\", \"volatile\"}:\n                raise ValueError(\n                    f\"assembly slot {slot.id!r} has unknown stability {slot.stability!r}\"\n                )\n            try:\n                content_json = _canonical_json(slot.content)\n                content = json.loads(content_json)\n            except (TypeError, ValueError):\n                raise ValueError(\n                    f\"assembly slot {slot.id!r} content is not JSON-serializable\"\n                ) from None\n            if slot.stability != \"volatile\":\n                key = (options.session_id, slot.id)\n                content_hash = _sha256_hex(content_json)\n                with self._assembly_hash_lock:\n                    previous = self._assembly_hash_ledger.get(key)\n                    if previous is not None and previous != content_hash:\n                        raise AssemblyStabilityError(slot.id)\n                    self._assembly_hash_ledger[key] = content_hash\n            normalized.append(AssemblySlot(slot.id, slot.stability, content))\n\n        ordered = [\n            slot\n            for stability in (\"stable\", \"session\", \"volatile\")\n            for slot in normalized\n            if slot.stability == stability\n        ]\n        prefix_slots = [slot for slot in ordered if slot.stability != \"volatile\"]\n        volatile_slots = [slot for slot in ordered if slot.stability == \"volatile\"]\n        breakpoints: list[str] = []\n\n        if provider == \"anthropic\":\n            tools_slot = next(\n                (slot for slot in prefix_slots if slot.id == \"tools\" and isinstance(slot.content, list)),\n                None,\n            )","sourceCodeStart":425,"sourceCodeEnd":461,"githubUrl":"https://github.com/JuliusBrussee/caveman/blob/27d5a3981a347890211bb1bf2439e5c821a63bc9/packages/sdk/python/caveman_cloud/core.py#L425-L461","documentation":"Error \"assembly slot {slot_id!r} changed after being declared stable\" thrown in JuliusBrussee/caveman.","triggerScenarios":"Thrown at packages/sdk/python/caveman_cloud/core.py:443 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Do not mutate a slot after declaring it stable; create a new slot version instead."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"27d5a3981a347890211bb1bf2439e5c821a63bc9","analyzedAt":"2026-08-15T09:26:11.751Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}