ADR-0009: Dev mode versus strict mode

Status: accepted Date: 2026-09-20

Context

The toolkit's own scripts (pkg_action.py, br2-ns.sh) are inputs of every action: a change to them must rebuild everything, or a cache hit would hide a behaviour change. During development that is a two-hour penalty for editing a comment.

Decision

Two modes. Strict (the default; always used by br2 build and br2 matrix): the scripts are declared inputs. Dev (br2 dev, br2.dev_tools=true): the scripts are referenced by path and are not inputs, so editing them changes no action key. Dev results are never used as numbers, and a dev-mode success must be repeated strict before it is trusted.

Consequences

• Easier: a toolkit edit no longer rebuilds the compiler; the edit-and-retry loop on a single package is minutes.
• Harder: dev-mode results can be stale against a script change. Dev keys are also different from strict ones, so a dev build does not warm the cache a strict build will use.
• The separation is enforced by construction, not by discipline: matrix passes dev_tools=false itself.