fix(daemon): warn and retry interrupted clipboard probes

packages/daemon/src/domain/slow-op-recorder.ts

@@ -3,7 +3,6 @@ import { performance } from "node:perf_hooks";
 import { Worker } from "node:worker_threads";
 import type { MiddlewareHandler } from "hono";
 
-export const SLOW_OPERATION_BARRIER_TIMEOUT_MS = 250;
 export const SLOW_OPERATION_THRESHOLD_MS = 250;
 export const SLOW_OPERATION_ROTATION_BYTES = 1024 * 1024;
 export const SLOW_OPERATION_ROTATION_COUNT = 3;
@@ -89,7 +88,6 @@ interface SlowOpRecorderOptions {
   maxBytes?: number;
   rotationCount?: number;
   slowThresholdMs?: number;
-  barrierTimeoutMs?: number;
 }
 
 interface Span {
@@ -141,13 +139,7 @@ const WORKER_SOURCE = String.raw`
       ok = false;
       error = caught instanceof Error ? caught.message : String(caught);
     }
-    if (message.signal) {
-      const state = new Int32Array(message.signal);
-      Atomics.store(state, 0, ok ? 1 : 2);
-      Atomics.notify(state, 0);
-    } else if (message.id) {
-      parentPort.postMessage({ id: message.id, ok, error });
-    }
+    if (message.id) parentPort.postMessage({ id: message.id, ok, error });
   });
 `;
 
@@ -157,7 +149,6 @@ export class SlowOpRecorder implements SlowOperationInstrumentation {
   private readonly maxBytes: number;
   private readonly rotationCount: number;
   private readonly slowThresholdMs: number;
-  private readonly barrierTimeoutMs: number;
   private readonly pending = new Map<string, { resolve: () => void; reject: (error: unknown) => void }>();
   private degraded: SlowOperationSnapshot = { healthy: true };
   private degradedHandler?: (snapshot: Required<Pick<SlowOperationSnapshot, "reason" | "site">>) => void;
@@ -181,7 +172,6 @@ export class SlowOpRecorder implements SlowOperationInstrumentation {
     this.maxBytes = options.maxBytes ?? SLOW_OPERATION_ROTATION_BYTES;
     this.rotationCount = options.rotationCount ?? SLOW_OPERATION_ROTATION_COUNT;
     this.slowThresholdMs = options.slowThresholdMs ?? SLOW_OPERATION_THRESHOLD_MS;
-    this.barrierTimeoutMs = options.barrierTimeoutMs ?? SLOW_OPERATION_BARRIER_TIMEOUT_MS;
     this.worker = new Worker(WORKER_SOURCE, { eval: true, execArgv: [] });
     this.worker.unref();
     this.worker.on("message", (message: { id?: string; ok?: boolean }) => {
@@ -220,27 +210,10 @@ export class SlowOpRecorder implements SlowOperationInstrumentation {
 
   beginSyncSpan(site: string): Span {
     const span: Span = { spanId: randomUUID(), site, startedAt: performance.now() };
-    const signal = new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT);
-    const state = new Int32Array(signal);
-    try {
-      this.worker.postMessage({
-        type: "append",
-        signal,
-        logPath: this.logPath,
-        maxBytes: this.maxBytes,
-        rotationCount: this.rotationCount,
-        record: { v: 1, ts: new Date().toISOString(), spanId: span.spanId, phase: "begin", site },
-      });
-    } catch {
-      // Synchronous postMessage failure means the Worker is gone: degrade
-      // through the terminal transition but still return the span so the
-      // wrapped operation runs to completion (its value/error stays exact).
-      this.handleTerminalFailure("recorder_post_failed", site);
-      return span;
-    }
-    const wait = Atomics.wait(state, 0, 0, this.barrierTimeoutMs);
-    if (wait === "timed-out") this.markDegraded("begin_barrier_timeout", site);
-    else if (Atomics.load(state, 0) !== 1) this.markDegraded("begin_barrier_failed", site);
+    // Queue before the operation without waiting on worker startup or fsync. The
+    // worker can write even while the main thread is wedged; only flush/close
+    // acknowledge durability. A crash before the worker appends can lose begin.
+    this.appendAsync({ v: 1, ts: new Date().toISOString(), spanId: span.spanId, phase: "begin", site });
     return span;
   }
 

packages/daemon/src/domain/tmux-option-defaults.ts

@@ -1,6 +1,6 @@
-import { spawnSync } from "node:child_process";
+import { execFile } from "node:child_process";
 import type { TmuxAdapter } from "../adapters/tmux.js";
-import { runSyncSite } from "./sync-site-wrap.js";
+import { runAsyncSite } from "./sync-site-wrap.js";
 
 export interface TmuxOptionDefaultsDeps {
   tmuxAdapter: TmuxAdapter;
@@ -17,11 +17,11 @@ export interface TmuxOptionDefaultsDeps {
    */
   platform?: NodeJS.Platform;
   /**
-   * OPR.0.4.6.02 S1 — cheap `command -v <bin>` probe for the linux
-   * copy-command fallback chain. Defaults to a real shell probe; injectable
+   * OPR.0.4.6.02 S1 — asynchronous `command -v <bin>` probe for the linux
+   * copy-command fallback chain. Defaults to a bounded asynchronous shell probe; injectable
    * for deterministic tests.
    */
-  hasCommand?: (bin: string) => boolean;
+  hasCommand?: (bin: string) => boolean | Promise<boolean>;
 }
 
 /**
@@ -44,7 +44,7 @@ export class TmuxOptionDefaultsApplier {
   private tmuxAdapter: TmuxAdapter;
   private readTmuxOptionDefaults: () => { statusBar: boolean };
   private platform: NodeJS.Platform;
-  private hasCommand: (bin: string) => boolean;
+  private hasCommand: (bin: string) => boolean | Promise<boolean>;
   private serverDefaultsAsserted = false;
 
   constructor(deps: TmuxOptionDefaultsDeps) {
@@ -120,7 +120,14 @@ export class TmuxOptionDefaultsApplier {
       warnings.push(`tmux "set-clipboard" server option not set: ${clip.message}`);
     }
 
-    const copyCommand = resolveCopyCommand(this.platform, this.hasCommand);
+    let copyCommand: string | null;
+    try {
+      copyCommand = await resolveCopyCommand(this.platform, this.hasCommand);
+    } catch {
+      this.serverDefaultsAsserted = false;
+      warnings.push("Clipboard lookup interrupted (250 ms limit); copy-command left unchanged (OSC 52 if unset). Will retry on the next fresh session.");
+      return;
+    }
     if (copyCommand !== null) {
       const cc = await this.tmuxAdapter.setServerOption("copy-command", copyCommand);
       if (!cc.ok) {
@@ -141,14 +148,14 @@ export class TmuxOptionDefaultsApplier {
  * Pure: platform + a `command -v` probe in, the command string (or null)
  * out. One table, no side effects — the applier decides whether to write.
  */
-export function resolveCopyCommand(
+export async function resolveCopyCommand(
   platform: NodeJS.Platform,
-  hasCommand: (bin: string) => boolean,
-): string | null {
+  hasCommand: (bin: string) => boolean | Promise<boolean>,
+): Promise<string | null> {
   if (platform === "darwin") return "pbcopy";
   if (platform === "linux") {
-    if (hasCommand("wl-copy")) return "wl-copy";
-    if (hasCommand("xclip")) return "xclip -selection clipboard -i";
+    if (await hasCommand("wl-copy")) return "wl-copy";
+    if (await hasCommand("xclip")) return "xclip -selection clipboard -i";
     return null;
   }
   return null;
@@ -156,16 +163,18 @@ export function resolveCopyCommand(
 
 /**
  * OPR.0.4.6.02 S1 — default `command -v <bin>` probe (POSIX shell builtin).
- * Returns true when the binary resolves on PATH. Cheap + best-effort; any
- * failure (spawn error, non-shell env) reads as absent.
+ * Returns true when the binary resolves on PATH. A killed probe rejects so
+ * the applier can warn and retry; other failures read as absent.
  */
-function defaultHasCommand(bin: string): boolean {
+async function defaultHasCommand(bin: string): Promise<boolean> {
   try {
-    const r = runSyncSite("tmux_options.command_v", () =>
-      spawnSync(`command -v ${bin}`, { shell: true, stdio: "ignore" })
-    );
-    return r.status === 0;
-  } catch {
+    return await runAsyncSite("tmux_options.command_v", () => new Promise<boolean>((resolve, reject) => {
+      execFile("/bin/sh", ["-c", 'command -v "$1"', "--", bin], {
+        timeout: 250, killSignal: "SIGKILL", maxBuffer: 1024,
+      }, error => error?.killed ? reject(error) : resolve(!error));
+    }));
+  } catch (error) {
+    if ((error as { killed?: boolean } | null)?.killed) throw error;
     return false;
   }
 }

packages/daemon/test/slow-op-recorder.test.ts

@@ -5,7 +5,7 @@ import os from "node:os";
 import path from "node:path";
 import { pathToFileURL } from "node:url";
 import type { Worker } from "node:worker_threads";
-import { afterEach, describe, expect, it } from "vitest";
+import { afterEach, describe, expect, it, vi } from "vitest";
 import { Hono } from "hono";
 import { createDaemon } from "../src/startup.js";
 import { createSlowOpRequestMiddleware } from "../src/domain/slow-op-recorder.js";
@@ -67,12 +67,37 @@ afterEach(() => {
 });
 
 describe("SlowOpRecorder locked instrumentation contract", () => {
+  it("returns promptly while begin acknowledgements are delayed", async () => {
+    const mod = await loadRecorderModule();
+    if (!mod) throw new Error("recorder module missing");
+    const logPath = path.join(tempDir(), "pending.jsonl");
+    const recorder = new mod.SlowOpRecorder({ logPath });
+    const worker: Worker = (recorder as any).worker;
+    const post = worker.postMessage;
+    const held: unknown[] = [];
+    worker.postMessage = message => {
+      if (message?.record?.phase === "begin") held.push(message);
+      else post.call(worker, message);
+    };
+    try {
+      const start = performance.now();
+      const values = [1, 2, 3].map(value => recorder.runSync("test.delayed.begin", () => value));
+      const elapsedMs = performance.now() - start;
+      expect(values).toEqual([1, 2, 3]);
+      expect(held).toHaveLength(3);
+      expect(elapsedMs).toBeLessThan(100);
+    } finally {
+      worker.postMessage = post;
+      for (const message of held) post.call(worker, message);
+      await recorder.close();
+    }
+  });
+
   it("pins the absolute boundary, rotation, filename, and secret-safe record contract", async () => {
     const mod = await loadRecorderModule();
     expect(mod, "slow-op-recorder production module is missing").not.toBeNull();
     if (!mod) return;
 
-    expect(mod.SLOW_OPERATION_BARRIER_TIMEOUT_MS).toBe(250);
     expect(mod.SLOW_OPERATION_THRESHOLD_MS).toBe(250);
     expect(mod.SLOW_OPERATION_ROTATION_BYTES).toBe(1024 * 1024);
     expect(mod.SLOW_OPERATION_ROTATION_COUNT).toBe(3);
@@ -85,9 +110,6 @@ describe("SlowOpRecorder locked instrumentation contract", () => {
     process.env.OPENRIG_TEST_SECRET = secret;
     try {
       const value = recorder.runSync("test.sync.boundary", () => {
-        const records = fs.readFileSync(logPath, "utf8");
-        expect(records).toContain('"phase":"begin"');
-        expect(records).toContain('"site":"test.sync.boundary"');
         return 41;
       });
       expect(value).toBe(41);
@@ -107,88 +129,34 @@ describe("SlowOpRecorder locked instrumentation contract", () => {
     }
   });
 
-  it("leaves a durable open span after the begin barrier and exposes fail-visible degradation", async () => {
+  it("flushes a queued open span and exposes acknowledged write failure in health", async () => {
     const mod = await loadRecorderModule();
-    expect(mod, "slow-op-recorder production module is missing").not.toBeNull();
-    if (!mod) return;
-
+    if (!mod) throw new Error("recorder module missing");
     const dir = tempDir();
-    const logPath = path.join(dir, "slow-operations.jsonl");
+    const logPath = path.join(dir, "open.jsonl");
     const recorder = new mod.SlowOpRecorder({ logPath });
-    const span = recorder.beginSyncSpan("test.sync.wedge");
-    expect(span).toBeTruthy();
-    const records = await readRecords(logPath);
-    expect(records).toHaveLength(1);
-    expect(records[0]).toMatchObject({ phase: "begin", site: "test.sync.wedge" });
-    expect(recorder.snapshot()).toMatchObject({ healthy: true });
+    recorder.beginSyncSpan("test.sync.wedge");
+    await recorder.flush();
+    expect(await readRecords(logPath)).toMatchObject([{ phase: "begin", site: "test.sync.wedge" }]);
     await recorder.close();
 
-    const degraded = new mod.SlowOpRecorder({
-      logPath: path.join(dir, "degraded.jsonl"),
-      barrierTimeoutMs: 0,
-    });
+    const degraded = new mod.SlowOpRecorder({ logPath: dir });
     const oldNoKernel = process.env.OPENRIG_NO_KERNEL;
     process.env.OPENRIG_NO_KERNEL = "1";
-    const daemon = await createTestDaemon({
-      dbPath: ":memory:",
-      tmuxExec: async () => "",
-      cmuxExec: async () => "",
-      slowOpRecorder: degraded,
-    } as never);
+    const daemon = await createTestDaemon({ dbPath: ":memory:", tmuxExec: async () => "", cmuxExec: async () => "", slowOpRecorder: degraded } as never);
     try {
-      const worker: Worker = (degraded as any).worker;
-      const postMessage = worker.postMessage;
-      let intercepted = 0;
-      let withheldSignal: SharedArrayBuffer | undefined;
-      try {
-        worker.postMessage = (message, transferList) => {
-          if (message?.type === "append"
-            && message.record?.phase === "begin"
-            && message.record?.site === "test.sync.degraded"
-            && message.signal instanceof SharedArrayBuffer) {
-            intercepted++;
-            const { signal, ...withoutSignal } = message;
-            withheldSignal = signal;
-            // Append through the real worker, but withhold this acknowledgement.
-            return postMessage.call(worker, withoutSignal, transferList);
-          }
-          return postMessage.call(worker, message, transferList);
-        };
-        expect(degraded.runSync("test.sync.degraded", () => "continued")).toBe("continued");
-      } finally {
-        worker.postMessage = postMessage;
-      }
-      expect(intercepted).toBe(1);
-      expect(worker.postMessage).toBe(postMessage);
-      expect(withheldSignal).toBeInstanceOf(SharedArrayBuffer);
-      expect(new Int32Array(withheldSignal!)[0]).toBe(0);
-      expect(degraded.snapshot()).toMatchObject({
-        healthy: false,
-        reason: "begin_barrier_timeout",
-        site: "test.sync.degraded",
-      });
-
-      const healthResponse = await daemon.app.request("/healthz");
-      expect(await healthResponse.json()).toMatchObject({
-        status: "ok",
-        slowOperations: {
-          healthy: false,
-          reason: "begin_barrier_timeout",
-          site: "test.sync.degraded",
-        },
-      });
+      expect(degraded.runSync("test.sync.degraded", () => "continued")).toBe("continued");
+      await expect(degraded.flush()).rejects.toBeInstanceOf(mod.SlowOpRecorderWriteError);
+      expect(degraded.snapshot()).toMatchObject({ healthy: false, reason: "recorder_write_failed", site: "recorder.worker" });
+      const response = await daemon.app.request("/healthz");
+      expect(await response.json()).toMatchObject({ status: "ok", slowOperations: { healthy: false, reason: "recorder_write_failed" } });
       const observations = daemon.deps.streamStore!.list();
       expect(observations).toHaveLength(1);
-      expect(observations[0]!.body).toContain("begin_barrier_timeout");
-      expect(observations[0]!.body).toContain("test.sync.degraded");
-      await degraded.flush();
-      const degradedRecords = await readRecords(path.join(dir, "degraded.jsonl"));
-      expect(degradedRecords.filter((record) => record.phase === "begin"
-        && record.site === "test.sync.degraded")).toHaveLength(1);
+      expect(observations[0]!.body).toContain("recorder_write_failed");
     } finally {
       daemon.eventLoopMonitor.stop();
       daemon.db.close();
-      await degraded.close();
+      await degraded.close().catch(() => {});
       if (oldNoKernel === undefined) delete process.env.OPENRIG_NO_KERNEL;
       else process.env.OPENRIG_NO_KERNEL = oldNoKernel;
     }
@@ -211,20 +179,17 @@ describe("SlowOpRecorder locked instrumentation contract", () => {
       });
       expect(value).toBe("continued");
       expect(ran).toBe(true);
-      expect(recorder.snapshot()).toEqual({
-        healthy: false,
-        reason: "begin_barrier_failed",
-        site: "test.sync.observer_failure",
-      });
+      await expect(recorder.flush()).rejects.toBeInstanceOf(mod.SlowOpRecorderWriteError);
+      expect(recorder.snapshot()).toEqual({ healthy: false, reason: "recorder_write_failed", site: "recorder.worker" });
     } finally {
       // This recorder's log path is intentionally unwritable (to force the
-      // begin-barrier failure above), so close() now correctly rejects on the
+      // asynchronously acknowledged write failure above), so close() now correctly rejects on the
       // latched lost-write durability — tolerate it in teardown.
       await recorder.close().catch(() => {});
     }
   });
 
-  it("durably records an open span before a main-thread sync wedge is killed", async () => {
+  it("writes a queued begin while the main thread is wedged, before a later kill", async () => {
     const dir = tempDir();
     const logPath = path.join(dir, "crash.jsonl");
     fs.writeFileSync(logPath, "", { mode: 0o600 });
@@ -278,6 +243,7 @@ describe("SlowOpRecorder locked instrumentation contract", () => {
         });
       });
       expect(callbackEvidence).toEqual({ isMainThread: true, threadId: 0 });
+      await vi.waitFor(async () => expect(await readRecords(logPath)).toMatchObject([{ phase: "begin", site: "test.sync.crash" }]));
       child.kill("SIGKILL");
       await once(child, "exit");
 
@@ -351,7 +317,7 @@ describe("SlowOpRecorder locked instrumentation contract", () => {
     expect(JSON.stringify(requests)).not.toContain("must-not-appear");
   });
 
-  it("wraps all nine accepted sync calls without moving them off the main thread", () => {
+  it("keeps the accepted slow-operation site labels", () => {
     const srcRoot = path.resolve(import.meta.dirname, "../src");
     for (const [relativePath, sites] of expectedSites) {
       const source = fs.readFileSync(path.join(srcRoot, relativePath), "utf8");
@@ -496,7 +462,7 @@ describe("SlowOpRecorder locked instrumentation contract", () => {
     expect((await app.request("/definitely-missing")).status).toBe(404);
   });
 
-  it("drives the real tmux command-v spawnSync site through a hermetic daemon", async () => {
+  it("drives the asynchronous tmux command-v site through a hermetic daemon", async () => {
     const mod = await loadRecorderModule();
     expect(mod, "slow-op-recorder production module is missing").not.toBeNull();
     if (!mod) return;

packages/daemon/test/tmux-option-defaults-timeout.test.ts

@@ -0,0 +1,45 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import type { TmuxAdapter } from "../src/adapters/tmux.js";
+import { TmuxOptionDefaultsApplier } from "../src/domain/tmux-option-defaults.js";
+
+const execute = vi.hoisted(() => vi.fn());
+vi.mock("node:child_process", () => ({ execFile: execute }));
+beforeEach(() => { execute.mockReset(); });
+
+describe("clipboard discovery deadline", () => {
+  it.each([null, "custom-copy"])("warns and retries a killed default probe, preserving %j", async initial => {
+    let copyCommand = initial;
+    const setServerOption = vi.fn(async (name: string, value: string) => {
+      if (name === "copy-command") copyCommand = value;
+      return { ok: true };
+    });
+    const adapter = { setSessionOption: async () => ({ ok: true }), setServerOption } as unknown as TmuxAdapter;
+    execute.mockImplementationOnce((_file, _args, options, callback) => {
+      expect(options).toMatchObject({ timeout: 250, killSignal: "SIGKILL" });
+      callback(Object.assign(new Error("probe deadline"), { killed: true }));
+    }).mockImplementationOnce((_file, _args, _options, callback) => callback(null));
+    const applier = new TmuxOptionDefaultsApplier({ tmuxAdapter: adapter, platform: "linux" });
+    const warnings = await applier.applyToFreshSession("first@test");
+    expect(warnings).toHaveLength(1);
+    expect(warnings[0]).toMatch(/clipboard.*250 ms/i);
+    expect(warnings[0]).toMatch(/retry/i);
+    expect(copyCommand).toBe(initial);
+    expect(execute).toHaveBeenCalledTimes(1);
+    expect(await applier.applyToFreshSession("next@test")).toEqual([]);
+    expect(copyCommand).toBe("wl-copy");
+    expect(execute).toHaveBeenCalledTimes(2);
+    expect(await applier.applyToFreshSession("later@test")).toEqual([]);
+    expect(execute).toHaveBeenCalledTimes(2);
+  });
+
+  it("memoizes confirmed absence without a deadline warning", async () => {
+    execute.mockImplementation((_file, _args, _options, callback) => callback(Object.assign(new Error("absent"), { code: 1 })));
+    const setServerOption = vi.fn(async () => ({ ok: true }));
+    const adapter = { setSessionOption: async () => ({ ok: true }), setServerOption } as unknown as TmuxAdapter;
+    const applier = new TmuxOptionDefaultsApplier({ tmuxAdapter: adapter, platform: "linux" });
+    expect(await applier.applyToFreshSession("first@test")).toEqual([]);
+    expect(await applier.applyToFreshSession("next@test")).toEqual([]);
+    expect(execute).toHaveBeenCalledTimes(2);
+    expect(setServerOption).not.toHaveBeenCalledWith("copy-command", expect.anything());
+  });
+});

packages/daemon/test/tmux-option-defaults.test.ts

@@ -23,6 +23,24 @@ function mockAdapter(overrides?: {
 }
 
 describe("TmuxOptionDefaultsApplier", () => {
+  it("awaits an asynchronous clipboard lookup without holding unrelated work", async () => {
+    const { adapter, setServerOption } = mockAdapter();
+    let release!: (present: boolean) => void;
+    const pending = new Promise<boolean>(resolve => { release = resolve; });
+    const probe = vi.fn((bin: string) => bin === "wl-copy" ? pending : Promise.resolve(true));
+    let finished = false;
+    const applier = new TmuxOptionDefaultsApplier({ tmuxAdapter: adapter, platform: "linux", hasCommand: probe });
+    const applied = applier.applyToFreshSession("async-clipboard@test").then(value => { finished = true; return value; });
+    try {
+      await new Promise(resolve => setImmediate(resolve));
+      expect(finished).toBe(false);
+      expect(setServerOption).not.toHaveBeenCalledWith("copy-command", expect.anything());
+    } finally { release(false); }
+    expect(await applied).toEqual([]);
+    expect(probe.mock.calls.map(([bin]) => bin)).toEqual(["wl-copy", "xclip"]);
+    expect(setServerOption).toHaveBeenCalledWith("copy-command", "xclip -selection clipboard -i");
+  });
+
   it("sets mouse on + status off (default) on the given session via SESSION scope only", async () => {
     const { adapter, setSessionOption, setServerOption } = mockAdapter();
     // default reader (omitted) → statusBar false.
@@ -109,20 +127,20 @@ describe("TmuxOptionDefaultsApplier", () => {
   });
 });
 
-describe("resolveCopyCommand (pure per-platform table)", () => {
-  it("darwin → pbcopy", () => {
-    expect(resolveCopyCommand("darwin", () => false)).toBe("pbcopy");
+describe("resolveCopyCommand (pure per-platform table)", async () => {
+  it("darwin → pbcopy", async () => {
+    expect(await resolveCopyCommand("darwin", () => false)).toBe("pbcopy");
   });
-  it("linux → wl-copy when present", () => {
-    expect(resolveCopyCommand("linux", (b) => b === "wl-copy")).toBe("wl-copy");
+  it("linux → wl-copy when present", async () => {
+    expect(await resolveCopyCommand("linux", (b) => b === "wl-copy")).toBe("wl-copy");
   });
-  it("linux → xclip when wl-copy absent but xclip present", () => {
-    expect(resolveCopyCommand("linux", (b) => b === "xclip")).toBe("xclip -selection clipboard -i");
+  it("linux → xclip when wl-copy absent but xclip present", async () => {
+    expect(await resolveCopyCommand("linux", (b) => b === "xclip")).toBe("xclip -selection clipboard -i");
   });
-  it("linux → null when neither present (OSC 52 fallback)", () => {
-    expect(resolveCopyCommand("linux", () => false)).toBeNull();
+  it("linux → null when neither present (OSC 52 fallback)", async () => {
+    expect(await resolveCopyCommand("linux", () => false)).toBeNull();
   });
-  it("other platforms → null", () => {
-    expect(resolveCopyCommand("win32", () => true)).toBeNull();
+  it("other platforms → null", async () => {
+    expect(await resolveCopyCommand("win32", () => true)).toBeNull();
   });
 });