pixtuoid 0.9.0

Terminal pixel-art office for AI coding agents
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
//! The async runtime glue: builds the tokio runtime, spawns the reducer
//! task + sources, binds the hook socket, and drives either the TUI or the
//! headless summary loop until Ctrl-C.
//!
//! Split out of `runtime/mod.rs` so this file — structurally unreachable by
//! any headless test (real tokio runtime + `block_on` + `ctrl_c` + socket
//! bind; see issue #103) — can be excluded from coverage on its own, while
//! the tested helpers (`RunConfig`, capacity math, `summarize`) keep full
//! coverage accounting in the parent module. One exception: `headless_loop`'s
//! signal handling takes the ctrl_c future as an injected seam, so its
//! registration-failure arm IS unit-tested here (the file stays
//! coverage-excluded regardless).

use std::path::PathBuf;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
use std::time::{Duration, SystemTime};

use anyhow::Result;
use pixtuoid_core::source::antigravity::AntigravitySource;
use pixtuoid_core::source::claude_code::ClaudeCodeSource;
use pixtuoid_core::source::codex::CodexSource;
use pixtuoid_core::source::copilot::CopilotSource;
use pixtuoid_core::source::daemon::{self, PresenceMsg};
use pixtuoid_core::source::hook::HookRouter;
use pixtuoid_core::source::jsonl::ChildEndUnclaims;
use pixtuoid_core::source::manager::SourceManager;
use pixtuoid_core::source::registry;
use pixtuoid_core::source::DynSource;
use pixtuoid_core::state::MAX_FLOORS;
use pixtuoid_core::{AgentEvent, Reducer, SceneState, TaggedReceiver, Transport};
use tokio::sync::{mpsc, watch};

use super::{
    boot_capacities_for, cap_boot_capacities, summarize, ConnectedSources, RunConfig, SceneRx,
    FALLBACK_DESKS,
};

pub fn run(cfg: RunConfig) -> Result<()> {
    let rt = tokio::runtime::Builder::new_multi_thread()
        .enable_all()
        .build()?;
    rt.block_on(async move { run_async(cfg).await })
}

async fn run_async(cfg: RunConfig) -> Result<()> {
    let RunConfig {
        socket,
        projects_root,
        codex_sessions_root,
        pack_dir,
        desk_cap,
        headless,
        config_path,
        theme,
        pets,
        connected,
        log_path,
    } = cfg;
    // The live, shared connected-source set: the reducer-task gate reads it, the
    // Sources panel mutates it. Seeded from the resolved boot flags.
    let connected = ConnectedSources::new(connected);
    // The runtime source set, built in ONE place (`build_source_set`): the
    // `HookRouter` (the shared-socket owner — every source's hooks ride it) plus
    // the transcript-bearing watchers (CC / Antigravity / Codex / Copilot). The
    // hook-only sources (Reasonix / CodeWhale / opencode / Cursor) and the daemon
    // (OpenClaw) have no watchable JSONL — their payloads ride the router's socket,
    // attributed per-payload by `_pixtuoid_source` — so they have no entry here.
    // Resolve the bound socket (Unix) / pipe (Windows) the HookRouter binds; the
    // Sources panel shows the same path (explicit --socket override, else default).
    let socket_path = socket.unwrap_or_else(ClaudeCodeSource::default_socket_path);
    // Daemon-presence SIDE channel (invariant #2: NOT the AgentEvent channel). The
    // HookRouter demux decodes daemon payloads into source-tagged presence deltas
    // sent here; the shared exit watch drains gateway-pid deaths into the SAME
    // channel as `(source, PidExited)`; the reducer task merges both into
    // SceneState::daemons.
    let (presence_tx, presence_rx) = tokio::sync::mpsc::unbounded_channel::<PresenceMsg>();
    let presence_exit_watch = daemon::spawn_presence_exit_watch(presence_tx.clone());
    let sources = build_source_set(
        socket_path.clone(),
        projects_root,
        codex_sessions_root,
        Some(presence_tx),
    );

    let (tx, rx) = mpsc::channel::<(Transport, AgentEvent)>(256);
    let boot_caps: [usize; MAX_FLOORS] = match (desk_cap, headless) {
        // Headless: no terminal to measure. Honor the cap as-is, else the fallback.
        (Some(cap), true) => [cap; MAX_FLOORS],
        (None, true) => [FALLBACK_DESKS; MAX_FLOORS],
        // Interactive: measure the real per-floor layout capacity FIRST, then clamp
        // to the optional cap. Clamping (not `[cap; _]`) keeps the boot atomics from
        // being seeded above the layout's real capacity — `fetch_max` only grows, so
        // an over-seed strands agents on non-existent desks until the terminal grows.
        (cap, false) => cap_boot_capacities(compute_boot_capacities(), cap),
    };
    let (scene_tx, scene_rx) = watch::channel(Arc::new(SceneState::new(boot_caps)));

    let floor_caps: Arc<[AtomicUsize; MAX_FLOORS]> =
        Arc::new(std::array::from_fn(|i| AtomicUsize::new(boot_caps[i])));

    tokio::spawn(reducer_task(
        rx,
        scene_tx,
        Arc::clone(&floor_caps),
        connected.clone(),
        presence_rx,
        presence_exit_watch,
    ));

    // Source-health side channel (#157): a fatal source exit must reach the
    // TUI footer — in default TUI mode tracing only reaches the log file, and
    // the office silently freezing is the worst failure class. Deliberately
    // NOT an AgentEvent: the one event channel carries agent activity (its
    // Transport tag drives hook-wins dedup), not source lifecycle.
    let (health_tx, health_rx) = tokio::sync::watch::channel(Vec::new());
    let mut manager = SourceManager::new();
    for src in sources {
        manager = manager.with_source(src);
    }
    let _source_handles = manager.spawn_with_health(tx, health_tx);

    if headless {
        headless_loop(scene_rx, health_rx).await
    } else {
        crate::tui::run_tui(
            scene_rx,
            pack_dir,
            floor_caps,
            theme,
            config_path,
            desk_cap,
            pets,
            health_rx,
            socket_path,
            connected,
            log_path,
        )
        .await
    }
}

/// Build the runtime source set `run_async` spawns — the ONE place that set is
/// constructed: the `HookRouter` (shared-socket owner) + the transcript-bearing
/// watchers. A transcript source registered in the core registry but missing here
/// (a silent "never spawns" no-op) is caught by
/// `build_source_set_wires_every_transcript_bearing_source_plus_the_hook_router`.
/// Each transcript source carries different typed config (CC's projects root,
/// Codex's sessions root), so this stays imperative rather than a registry-driven
/// loop — invariant #3's per-source-typed seam. Hook-only sources + the daemon
/// (OpenClaw) are absent by design — they ride the router's shared socket.
fn build_source_set(
    socket_path: PathBuf,
    projects_root: Option<PathBuf>,
    codex_sessions_root: Option<PathBuf>,
    presence_tx: Option<daemon::PresenceSender>,
) -> Vec<Box<dyn DynSource>> {
    let mut cc_src = ClaudeCodeSource::default_paths();
    if let Some(p) = projects_root {
        cc_src.projects_root = p;
    }
    let ag_src = AntigravitySource::default_paths();
    let copilot_src = CopilotSource::default_paths();

    let mut codex_src = CodexSource::default_paths();
    if let Some(p) = codex_sessions_root {
        codex_src.sessions_root = p;
    }

    // #246: ONE shared child-end un-claim handle. The HookRouter's hook tee is the
    // PRODUCER (every source's SubagentStop rides the one shared socket it owns);
    // both watchers CONSUME — each drains only the ids whose transcripts it claims
    // (AgentId is source-namespaced), so a Codex child's id waits for the Codex
    // watcher even though the router decoded its hook.
    let child_end_unclaims = ChildEndUnclaims::new();
    cc_src.child_end_unclaims = Some(child_end_unclaims.clone());
    codex_src.child_end_unclaims = Some(child_end_unclaims.clone());

    // The HookRouter owns the ONE shared hook socket every source's hooks ride;
    // it is the tee producer + the daemon-presence demux. CC/Codex are now pure
    // transcript watchers (consumers of the un-claim handle).
    let hook_router = HookRouter::new(socket_path)
        .with_child_end_unclaims(Some(child_end_unclaims))
        .with_presence_tx(presence_tx);

    vec![
        Box::new(hook_router) as Box<dyn DynSource>,
        Box::new(cc_src),
        Box::new(ag_src),
        Box::new(codex_src),
        Box::new(copilot_src),
    ]
}

/// The source id an event would register/refresh — so the Connection gate can
/// drop a disconnected source's events BEFORE they reach the reducer. The source
/// is NOT recoverable from an `AgentId` (it's a hash), so read it off the two
/// variants that carry it (a hook `Identity` is emitted ahead of every activity
/// event since #221, so a fresh hook session's first event self-identifies);
/// otherwise fall back to the existing slot's source. `None` (an identity-less
/// event for an unknown id) slips the gate once and is evicted on the next tick.
fn event_source<'a>(scene: &'a SceneState, ev: &'a AgentEvent) -> Option<&'a str> {
    match ev {
        AgentEvent::SessionStart { source, .. } | AgentEvent::Identity { source, .. }
            if !source.is_empty() =>
        {
            Some(source)
        }
        _ => scene.agents.get(&ev.agent_id()).map(|s| s.source.as_ref()),
    }
}

async fn reducer_task(
    mut rx: TaggedReceiver,
    scene_tx: watch::Sender<Arc<SceneState>>,
    floor_caps: Arc<[AtomicUsize; MAX_FLOORS]>,
    connected: ConnectedSources,
    mut presence_rx: tokio::sync::mpsc::UnboundedReceiver<PresenceMsg>,
    presence_exit_watch: Option<daemon::PresenceExitWatch>,
) {
    let mut reducer = Reducer::new();
    // Disabled once the presence channel closes (all senders dropped) so its
    // `recv() -> None` branch can't busy-loop the select.
    let mut presence_open = true;
    let initial_caps: [usize; MAX_FLOORS] =
        std::array::from_fn(|i| floor_caps[i].load(Ordering::Relaxed));
    let mut scene = SceneState::new(initial_caps);
    // 1-Hz tick so exit-grace sweeps run even when no new events arrive.
    let mut sweep_interval = tokio::time::interval(Duration::from_secs(1));
    sweep_interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
    loop {
        // Sync per-floor capacities from the shared atomics so the
        // auto-computed layout capacity propagates to next_free_desk().
        for (i, a) in floor_caps.iter().enumerate() {
            scene.floor_capacities[i] = a.load(Ordering::Relaxed);
        }
        tokio::select! {
            event = rx.recv() => {
                let Some((transport, ev)) = event else { break };
                let now = SystemTime::now();
                // Connection gate: drop a disconnected source's events before
                // they register/refresh a sprite. No scene change → no send.
                if event_source(&scene, &ev).is_some_and(|src| !connected.is_connected(src)) {
                    continue;
                }
                tracing::debug!(?transport, ?ev, "event");
                reducer.apply(&mut scene, ev, now, transport);
                if scene_tx.send(Arc::new(scene.clone())).is_err() {
                    tracing::warn!("scene channel closed — renderer dropped");
                    break;
                }
            }
            // Daemon-presence deltas — source-tagged `(source, delta)` (hook-derived
            // + `(source, PidExited)` from the shared exit watch) — merged into
            // SceneState::daemons, NEVER through Reducer::apply (which is
            // AgentId-pure). Invariant #2. N daemons route by the tuple's source.
            update = presence_rx.recv(), if presence_open => {
                match update {
                    Some(PresenceMsg {
                        source,
                        delta: update,
                    }) => {
                        let now = SystemTime::now();
                        // CONNECTION GATE (mirrors the AgentEvent arm above): a
                        // daemon DISCONNECTED in the Sources panel has its presence
                        // DROPPED — don't arm the exit watch, don't apply. Any
                        // lingering entry is walked out by the sweep-tick reconcile.
                        if connected.is_connected(&source) {
                            // Arm the instant abrupt-down watch on the gateway pid —
                            // from GatewayUp (gateway_start) OR PidSeen (#318: a
                            // mid-attach / reconnect that never saw gateway_start, so
                            // the pid rides a later event). `watch` is idempotent per
                            // pid; `apply_presence` owns the None-only adoption.
                            if let Some(ew) = presence_exit_watch.as_ref() {
                                if let Some(pid) = update.armable_pid() {
                                    ew.watch(&source, pid);
                                }
                            }
                            daemon::apply_presence(&mut scene, &source, update, now);
                            if scene_tx.send(Arc::new(scene.clone())).is_err() {
                                tracing::warn!("scene channel closed — renderer dropped");
                                break;
                            }
                        }
                    }
                    None => presence_open = false,
                }
            }
            _ = sweep_interval.tick() => {
                let now = SystemTime::now();
                // Reconcile the scene toward the connected-set: walk out (idempotently)
                // every sprite whose source is NOT connected. Stateless on purpose —
                // no prev-set bookkeeping — and keyed on the COMPLEMENT of the set
                // (not a registered-source list), so it ALSO evicts a blank-source
                // slot synthesized for an identity-less event that slipped the
                // per-event gate, closing that hole within one tick.
                let cur = connected.snapshot();
                reducer.reconcile_connected(&mut scene, &cur, now);
                reducer.tick(&mut scene, now);
                // Per-daemon presence reconcile + decay (registry-DRIVEN, N daemons):
                // a panel-disconnected daemon walks its mascot out (Down → walk-out →
                // DOWN_REMOVE removal — the presence side-channel is separate from the
                // AgentEvent gate), and every daemon decays busy→idle / up→down on
                // silence per its own TTL. A 2nd daemon needs no edit here.
                for (source, ttl) in registry::daemon_sources() {
                    if !connected.is_connected(source) {
                        daemon::mark_presence_down(&mut scene, source, now);
                    }
                    daemon::sweep_presence_ttl(&mut scene, source, ttl, now);
                }
                if scene_tx.send(Arc::new(scene.clone())).is_err() {
                    tracing::warn!("scene channel closed — renderer dropped");
                    break;
                }
            }
        }
    }
}

async fn headless_loop(
    scene_rx: SceneRx,
    health_rx: tokio::sync::watch::Receiver<Vec<pixtuoid_core::source::manager::SourceDeath>>,
) -> Result<()> {
    // ONE SIGINT listener for the loop's lifetime. A fresh `ctrl_c()` per
    // select! iteration drops the old listener while the sleep arm runs, and
    // tokio's process-global handler (installed once) suppresses default
    // termination — so a SIGINT landing in that gap notifies zero listeners
    // and is silently lost (the user must Ctrl-C twice). Created once here,
    // the subscription is continuous; the future is boxed so the loop can
    // disarm a registration FAILURE (a resolved future must never be polled
    // again). The signal future is INJECTED into the loop body so the
    // registration-failure arm is testable in-process (the real ctrl_c()
    // registers an unfakeable process-global handler).
    headless_loop_with_signal(scene_rx, health_rx, Box::pin(tokio::signal::ctrl_c())).await
}

async fn headless_loop_with_signal(
    mut scene_rx: SceneRx,
    mut health_rx: tokio::sync::watch::Receiver<Vec<pixtuoid_core::source::manager::SourceDeath>>,
    mut ctrl_c: std::pin::Pin<Box<dyn std::future::Future<Output = std::io::Result<()>> + Send>>,
) -> Result<()> {
    tracing::info!("pixtuoid headless mode — Ctrl-C to quit");
    let mut prev_summary = String::new();
    // Headless has no TUI footer (#157's sink for source deaths) and no
    // stderr subscriber guarantee — surface them in the summary stream, or a
    // dead transport reads as a silently empty office. Tracked by count: the
    // watch Vec only grows.
    let mut deaths_seen = 0usize;
    loop {
        tokio::select! {
            _ = tokio::time::sleep(Duration::from_millis(200)) => {
                let snapshot = scene_rx.borrow_and_update().clone();
                let summary = summarize(&snapshot);
                if summary != prev_summary {
                    println!("{summary}");
                    prev_summary = summary;
                }
            }
            Ok(()) = health_rx.changed() => {
                let deaths = health_rx.borrow_and_update().clone();
                for d in deaths.iter().skip(deaths_seen) {
                    println!("{}", super::format_source_death(d));
                }
                deaths_seen = deaths.len();
            }
            res = &mut ctrl_c => match res {
                Ok(()) => {
                    tracing::info!("shutting down");
                    return Ok(());
                }
                Err(e) => {
                    // A failed handler registration resolves Err on the FIRST
                    // poll. A wildcard match here exited headless mode
                    // instantly — silently, status 0 (the #157 class), on the
                    // exact CI/container surface where registration can be
                    // denied. Disarm the arm and keep serving: the default
                    // SIGINT disposition was never replaced, so Ctrl-C still
                    // terminates the process.
                    tracing::error!(
                        %e,
                        "Ctrl-C handler registration failed — headless loop \
                         continues; SIGINT falls back to the default disposition"
                    );
                    ctrl_c = Box::pin(std::future::pending());
                }
            }
        }
    }
}

fn compute_boot_capacities() -> [usize; MAX_FLOORS] {
    match crossterm::terminal::size().ok() {
        Some((cols, rows)) => boot_capacities_for(cols, rows),
        None => [FALLBACK_DESKS; MAX_FLOORS],
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use pixtuoid_core::source::manager::SourceDeath;

    type HealthPair = (
        watch::Sender<Vec<SourceDeath>>,
        watch::Receiver<Vec<SourceDeath>>,
    );

    fn channels() -> (watch::Sender<Arc<SceneState>>, SceneRx, HealthPair) {
        let (scene_tx, scene_rx) =
            watch::channel(Arc::new(SceneState::new([FALLBACK_DESKS; MAX_FLOORS])));
        (scene_tx, scene_rx, watch::channel(Vec::new()))
    }

    // The documented "a source registered in the core registry but NOT wired
    // into run_async passes every conformance/manifest test yet never spawns"
    // gap (core/CLAUDE.md) — closed. `build_source_set` constructs the shared-
    // socket `HookRouter` PLUS every transcript-bearing registered source
    // (`line_decoder().is_some()`); it reads names off the real boxes, so it
    // can't drift from a hand-maintained second list. Hook-only sources + the
    // daemon (OpenClaw) are absent by design (they ride the router's socket).
    #[test]
    fn build_source_set_wires_every_transcript_bearing_source_plus_the_hook_router() {
        use pixtuoid_core::source::{registry::descriptor_for, REGISTERED_SOURCES};
        use std::collections::BTreeSet;

        let sources = build_source_set(PathBuf::from("/tmp/pixtuoid-test.sock"), None, None, None);
        let built: BTreeSet<&str> = sources.iter().map(|s| s.name()).collect();

        // The HookRouter (infrastructure — owns the shared socket, NOT a
        // registered CLI) must be in the set so its fatal-bind death surfaces via
        // `spawn_with_health` (#157); it has no descriptor, so it's excluded from
        // the transcript-coverage check below.
        assert!(
            built.contains("hook-router"),
            "the shared-socket HookRouter must be spawned (else hook signals never decode)"
        );

        let transcript_built: BTreeSet<&str> = built
            .iter()
            .copied()
            .filter(|&n| n != "hook-router")
            .collect();
        let expected: BTreeSet<&str> = REGISTERED_SOURCES
            .iter()
            .copied()
            .filter(|&name| descriptor_for(name).is_some_and(|d| d.line_decoder().is_some()))
            .collect();
        assert_eq!(
            transcript_built, expected,
            "run_async's transcript-source wiring diverged from the registry: a \
             transcript-bearing source is registered but not built (it would never \
             spawn), or a built source isn't registered"
        );
    }

    // The Connection-gate seam: `event_source` decides which source an incoming
    // event belongs to so reducer_task can drop a disconnected source's events.
    // Carrying variants (SessionStart/Identity) self-identify; everything else
    // resolves via the existing slot; an unknown id with no carried source slips
    // the gate once (None) and is swept by the per-tick reconciler.
    #[test]
    fn event_source_extracts_source_for_the_connection_gate() {
        use pixtuoid_core::AgentId;
        let now = SystemTime::now();
        let mut scene = SceneState::new([FALLBACK_DESKS; MAX_FLOORS]);
        let mut reducer = Reducer::new();
        let id = AgentId::from_transcript_path("/p/a.jsonl");

        // SessionStart carries the source directly — even before the slot exists.
        let ss = AgentEvent::SessionStart {
            agent_id: id,
            source: "claude-code".into(),
            session_id: "s".into(),
            cwd: PathBuf::from("/repo"),
            parent_id: None,
        };
        assert_eq!(event_source(&scene, &ss), Some("claude-code"));

        // Identity likewise self-identifies.
        let idy = AgentEvent::Identity {
            agent_id: id,
            source: "codex".into(),
            session_id: "s".into(),
            cwd: None,
        };
        assert_eq!(event_source(&scene, &idy), Some("codex"));

        // A non-carrying event for an UNKNOWN id slips the gate (None) — the
        // reconciler is the safety net.
        let act = AgentEvent::ActivityStart {
            agent_id: id,
            tool_use_id: None,
            detail: None,
        };
        assert_eq!(event_source(&scene, &act), None);

        // Once registered, the same event resolves via the slot's source.
        reducer.apply(&mut scene, ss, now, Transport::Jsonl);
        assert_eq!(event_source(&scene, &act), Some("claude-code"));

        // An EMPTY source on a carrying variant falls through to the slot.
        let empty = AgentEvent::Identity {
            agent_id: id,
            source: String::new(),
            session_id: "s".into(),
            cwd: None,
        };
        assert_eq!(event_source(&scene, &empty), Some("claude-code"));
    }

    #[tokio::test(start_paused = true)]
    async fn headless_loop_shuts_down_on_a_delivered_signal() {
        let (_scene_tx, scene_rx, (_health_tx, health_rx)) = channels();
        headless_loop_with_signal(scene_rx, health_rx, Box::pin(async { Ok(()) }))
            .await
            .expect("a delivered Ctrl-C is a clean shutdown");
    }

    #[tokio::test(start_paused = true)]
    async fn headless_loop_keeps_serving_after_a_failed_signal_registration() {
        // A failed ctrl_c registration resolves Err on the first poll. The old
        // wildcard arm (`_ = &mut ctrl_c`) matched it and returned Ok(()) —
        // headless mode exited instantly, silently, status 0. The Err arm must
        // disarm itself instead: the loop keeps serving the scene/health arms,
        // so the timeout elapses (paused-clock time, so this is instant).
        let (_scene_tx, scene_rx, (_health_tx, health_rx)) = channels();
        let res = tokio::time::timeout(
            Duration::from_secs(5),
            headless_loop_with_signal(
                scene_rx,
                health_rx,
                Box::pin(async { Err(std::io::Error::other("sigaction denied")) }),
            ),
        )
        .await;
        assert!(
            res.is_err(),
            "the loop must still be running after a failed signal registration, got {res:?}"
        );
    }
}