fix(buck2): ship static_checks in the consumer rules product

[schickling-assistant]

Problem

The standalone consumer rules product is broken from current main in four independent ways, all reproduced by building the first downstream consumer against the locked provider:

1. The TypeScript package projection (schema 12) emits load("@rules//buck2:static_checks.bzl", ...) in every consumer BUCK file, but the rules product inventory never shipped buck2/static_checks.bzl:

From load at packages/@overeng/meters/BUCK:13
Caused by:
    File not found: rules//buck2/static_checks.bzl

2. nix build .#buck2-rules fails outright since feat(buck2): add standalone root and aggregate gates #1301/feat(buck2): move bounded Weaver checks #1302 switched the toolchains sources to @capabilities natively — the packager's --replace-fail substitutions find nothing:

substituteStream() in derivation buck2-rules: ERROR: pattern "//.buck2/capabilities:defs.bzl"
doesn't match anything in file '.../buck2-rules/buck2/toolchains/BUCK'

3. The projection emits workspace_dist / workspace_dependency_views on every package_tree(...) call, but the package_tree wrapper neither declared nor forwarded them:

error: Argument `workspace_dependency_views` occurs more than once

4. The toolchains, javascript, package_tools, and static_checks rules reference labels under packages/@overeng/buck2-tools (typescript-runner.ts, package_command_runtime, javascript_action_runtime, src/static-check-runner.ts, src/repository-policy-runner.ts), but the product shipped neither the runner sources nor the package, so every consumer target evaluation fails with package rules//packages/@overeng/buck2-tools does not exist.

All four reproduced on pristine main — pre-existing, not consumer-specific.

Goal

buck2-rules builds from main again, ships every file and label consumer projections reference, and the downstream standalone consumer builds both of its products end to end.

Decisions

• Extend the hand-maintained inventory (+ unit-test expectation) rather than deriving it from projection loads — derivation belongs to the static-checks migration (Migrate residual static checks to Buck2 #1344).
• Delete the two obsolete substituteInPlace calls instead of weakening to --replace: the sources now emit @capabilities refs directly.
• Mirror package_view's parameter shape in the package_tree wrapper (declare, default empty, fold workspace_dist into workspace_files).
• Generate a packages/@overeng/buck2-tools/BUCK in the packager mirroring the repository's own runtime targets, and alias the root runtime labels onto the package targets (root filegroups cannot source files from inside a nested package).

Verification

• devenv tasks run genie:run regenerates inventory.json with exactly the added entries; genie:check fresh; lint:check:format passes; genie:buck2:test 87 pass / 0 fail (includes the updated inventory expectation).
• nix build .#buck2-rules succeeds; the output ships buck2/static_checks.bzl, all five runner sources, and the nested package BUCK. Before this change the same build fails with the substitution error above.
• End to end (the real consumer gate): pinned a private downstream consumer to this branch, refreshed its stale fixed-output hash, and built both of its standalone Buck products — nix build .#geist-design-system .#meters succeeds and emits both tarball artifacts. Each of the four fixes was individually forced by this loop (the failure advanced one gap per fix).

Pre-flip deviations

• check:all not run locally: the shared builder is saturated by concurrent deploys and heavy builds. CI owns those lanes.

Complexity

No new abstractions — inventory entries, two dead lines removed, one wrapper parameterized to match its sibling, one mirrored package BUCK.

Concerns

• Migrate residual static checks to Buck2 #1344 adds repository_static_checks loads; if those reach consumer BUCK files the inventory may need further entries — flagged for coordination.

Friction & bottlenecks

• Bottleneck: shared nix builder saturation starved small builds (contract-test nix build --impure queued 28+ min).

References

• Follows refactor(buck2): make repository checks standalone #1323 / feat(buck2): add standalone root and aggregate gates #1301 / feat(buck2): move bounded Weaver checks #1302 (repository checks standalone).

Posted on behalf of @schickling

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