type.batch_capture_not_storable: A batch saves a value that can't be stored

A batch saves a value that can't be stored.

Area 12, Background work; not declinable; the next step is usually the agent's.

What a run saves (from:'s query's arguments, what each: and finished: capture, and key:) is kept as its type's JSON, so the run can resume after a crash or a deploy; a value an entity field couldn't hold, such as a request's Input, is refused, naming it:

example

action mark_on(item: Item, page: ItemPage) -> Unit {    assert item.seen == item.seen}action sweep_shelf(page: ItemPage) -> BatchRun {    return batches.each(from: items(page), each: item -> mark_on(item, page))}

jadpo checkcheck failed: 1 error, 2 files

error batches.each can't save page

--> main.jadpo:6:72

  |6 |     return batches.each(from: items(page), each: item -> mark_on(item, page))  |                                                                        ^^^^ `ItemPage` has no stored form

reason: What each: captures is worked out when the run starts and saved with it, as its type's JSON, so the run can resume after a crash or a deploy; page is ItemPage, an Input, the shape a request arrives in, where a record keeps an Object.
next: Pass something an entity field could hold instead, such as the id that finds page (agent)
rule: type.batch_capture_not_storable
help: https://jadpo.dev/docs/errors/type.batch_capture_not_storable