Replace text-grep cascade detection with a precomputed in-memory graph:
- Build a recipe_index of pkg_name → deps_csv (extracted from
[package]/[build] sections of recipe.toml).
- find_reverse_deps() queries the index in O(1) per package.
- Precompute once, query BFS in O(N) instead of O(N²).
Also fix a bug where empty target string would match every empty-deps
recipe, causing runaway BFS to all 3055 packages (was: 2m40s; now: 6s).
The script now correctly identifies which packages explicitly declare
a target as a [package] or [build] dependency. Implicit cross-compile
toolchain dependencies (relibc, base) are NOT tracked here — they
participate in build via the redoxer/cross setup, not via recipe
declarations. Tracking those requires a different mechanism.
Plan: local/docs/BUILD-SYSTEM-ROBUSTNESS-PLAN.md
Red Bear CI
b16e619691