D957 - A dispatch is captured to be replayed alone

Status: decided Date: 2026-10-24 known_by: measured

A guest compute dispatch can be written to disk with everything it was handed - its module, the guest-memory window it binds, push constants, groups, the images and buffers it binds - and run again alone by orbistoun-cli replay-dispatch, which reports each run's device time, whether the device was lost, and a hash of everything it left. A dispatch is captured before it is submitted when ORBISTOUN_CAPTURE_DISPATCH names its program, and after it fails when it is the one that lost the device. The capture is taken where every guest dispatch passes, from the inputs it already holds, and a replay hands them back through the same path, so a fix to that path is what the replay runs.

Why: Grand Theft Auto V's first in-world dispatch of the program at image+0x3dc3400 lost the device forty minutes into a run. Reproducing it meant booting the game again, and whether a change fixed it could only be seen at the end of another such run. A capture reproduces it in seconds, and two builds compare by the output hash.

Rejected:

• Copying each dispatch's inputs ahead of time, in case it fails: the memory window, on every dispatch.
• Capturing every program the first time it runs: a write for each new program, most of which never fail.