Loadbearing · checkpoint once, fork per mutation

haystack-answer-meta-2.7.0

2 inputs do not do what the pipeline claims. Found by running it, not by reading it.

forks from one checkpoint

10.99s

all 17 runs, in parallel (73.36s one after another)

6.7x

faster than running them in sequence

defects

One checkpoint, every fork

Every field, every mutation

field	should matter?	destroy	drop	nudge	verdict
request_id	no	same	same	same	inert
query	yes	moved	moved	moved	load-bearing
reply	yes	moved	moved	moved	load-bearing
meta.source_url	yes	same	same	same	SILENT PASSTHROUGH
meta.policy_version	yes	same	same	same	SILENT PASSTHROUGH

The evidence

meta.source_url · silent passthrough

Declared as an input that should change the output. It was destroyed, dropped and nudged in 3 separate forks, and the output never moved. The pipeline does not read it.

baseline output

answers: [{"data": "No, the 14-day return window has passed, but the warranty covers a repair.", "meta": {"model": "nemotron"}, "query": "Can I still return headphones …

after destroy (identical)

answers: [{"data": "No, the 14-day return window has passed, but the warranty covers a repair.", "meta": {"model": "nemotron"}, "query": "Can I still return headphones …

meta.policy_version · silent passthrough

Declared as an input that should change the output. It was destroyed, dropped and nudged in 3 separate forks, and the output never moved. The pipeline does not read it.

baseline output

answers: [{"data": "No, the 14-day return window has passed, but the warranty covers a repair.", "meta": {"model": "nemotron"}, "query": "Can I still return headphones …

after destroy (identical)

answers: [{"data": "No, the 14-day return window has passed, but the warranty covers a repair.", "meta": {"model": "nemotron"}, "query": "Can I still return headphones …

Baseline

input

request_id: req_8Kx2pd

query: Can I still return headphones after 20 days?

reply: No, the 14-day return window has passed, but the warranty covers a repair.

meta: {"source_url": "https://shop.example/help/returns-policy", "policy_version": "2026-09"}

output

answers: [{"data": "No, the 14-day return window has passed, but the warranty covers a repair.", "meta": {"model": "nemotron"}, "query": "Can I still return headphones …