D222 - A build names its commit

Status: decided Date: 2026-08-24

Every binary is stamped with the commit it was built from - the workflow's head SHA in CI, git otherwise, shortened only when it is plain hex, with -dirty for a modified tree - and shows it in the application and in every run report. With no commit it shows its own build time, in UTC.

Why: a result that cannot be tied to a tree cannot be reproduced, and the short SHA is the version number. A pull request's merge commit exists only inside the CI run. A local time shifts and makes two stamps incomparable.

Rejected:

• An unset field reading "unknown": defeats its only purpose.
• The pull request merge SHA: nobody can check it out.
• A compile-time constant in one crate: older than the binary it describes.