`aura --help` and `aura -h` are a newcomer's reflex first command, but
today they hit the unknown-subcommand error path: exit 2, empty stdout,
one-line `aura: usage: aura run` on stderr. For a C22 "newcomer sees a
populated trace" milestone the conventional help affordance returning
the error path is a first-contact friction.
This compile-clean RED pins the desired success-path contract: `--help`
and `-h` print non-empty usage to stdout and exit 0, and the usage names
the `run` subcommand. A negative-preservation assertion keeps an unknown
subcommand (`frobnicate`) on the exit-2 error path so the fix cannot
regress bad-args handling. Asserts structural facts only (exit code,
non-empty stdout, mentions `run`), not exact help prose.
refs #20
The Walking-skeleton milestone's closing seam: a real `aura run` binary that
bootstraps a built-in sample harness, runs it deterministically, and prints the
cycle-0009 metrics+manifest report as canonical JSON to stdout — the headline
C14 "run a sim, emit structured metrics" move, end-to-end, from a binary for the
first time.
Two deliverables:
- aura-std::Recorder — a reusable recording sink node (the glossary *sink* role,
C8/C22): a pure consumer (output: vec![]) over kinds.len() input columns,
holding an mpsc::Sender<(Timestamp, Vec<Scalar>)> as its out-of-graph
destination. mpsc keeps the engine's purity invariant (C7): no Rc/RefCell.
Supports all four base scalar kinds; returns None until every column is warm.
Promotes the shape the #[cfg(test)] fixtures already proved into a shipped,
reusable block (the fixtures stay as historical snapshots; de-dup is a later
tidy).
- aura-cli `run` subcommand — synthetic_prices / sample_harness / run_sample /
main. The sample harness (synthetic source → SMA(2)/SMA(4) → Sub → Exposure →
SimBroker → two Recorder sinks) is authored in plain Rust over the raw
Harness::bootstrap(nodes, sources, edges) API (C17/C20) — the open
experiment-builder DSL thread is deliberately not committed this cycle. main
hand-parses one subcommand: `run` prints run_sample().to_json() (exit 0),
anything else prints a one-line usage to stderr (exit 2). aura-cli gains
aura-std + aura-core path deps; the workspace stays zero-(external-)dependency.
The built-in synthetic stream (7 ticks, rises then reverses) yields a non-trivial
demo trace: equity [0,0,0,0,-0.08,-0.17,-0.13] → total_pips -0.13, max_drawdown
0.17, exposure_sign_flips 1. The run_sample unit test pins the integer flip count
exactly and the two f64 metrics within 1e-9 (the real run's float dust is ~7e-15,
confirming the tolerance); determinism is pinned exactly (two runs → identical
JSON). tests/cli_run.rs drives the built binary for the observable exit/stdout
contract.
manifest.commit is filled from option_env!("AURA_COMMIT") (defaults to
"unknown"); real HEAD capture via build.rs is deferred. Non-goals untouched:
experiment-builder DSL, aura new, Aura.toml schema, the data-server source (#7).
One deviation from the plan's verbatim code: a scoped
#[allow(clippy::type_complexity)] on sample_harness (its (Harness, Receiver,
Receiver) return tuple trips the lint under -D warnings) — consistent with the
identical allow on the build_two_sink_harness fixture in aura-engine. Verified
myself: cargo test --workspace (61 green, 0 red), clippy --all-targets
-D warnings (clean), cargo doc -D warnings (clean), and both smoke runs.
closes#8
Cargo workspace aura-core -> aura-engine -> aura-cli (bin `aura`) plus nodes/ for hot-reloadable cdylib node crates. Crate bodies are intentionally API-free; types arrive from the first spec. Adds the skills profile (.claude/dev-cycle-profile.yml), the project CLAUDE.md with the eight domain invariants, and the design-ledger skeleton.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Brummel