From e9233123ebf195a65f352983fc8b2116b40d14ec Mon Sep 17 00:00:00 2001
From: Tianyi Cui <53024+tianyicui@users.noreply.github.com>
Date: Wed, 29 Jul 2026 21:12:01 +0800
Subject: [PATCH] fix(skill): ignore unchanged missing-root probes

---
 packages/skill/skill-local/src/index.ts       | 30 ++++++++++++++-----
 .../tests/skill-local-watcher.spec.ts         | 25 ++++++++++++++++
 2 files changed, 48 insertions(+), 7 deletions(-)

diff --git a/packages/skill/skill-local/src/index.ts b/packages/skill/skill-local/src/index.ts
index 4ac5f101cd..ed68e84bcb 100644
--- a/packages/skill/skill-local/src/index.ts
+++ b/packages/skill/skill-local/src/index.ts
@@ -421,7 +421,7 @@ class SkillWatchManager {
 
   private openAncestorWatcher(state: RootWatchState, mode: Extract<RootWatchMode, { kind: 'ancestor' }>): WatchHandle {
     const listener = (_current: Stats, _previous: Stats): void => {
-      this.handleWatchEvent(state, mode, 'change', mode.nextPath)
+      void this.handleAncestorWatchEvent(state, mode)
     }
     watchFile(mode.nextPath, {
       persistent: false,
@@ -435,6 +435,25 @@ class SkillWatchManager {
     }
   }
 
+  private async handleAncestorWatchEvent(
+    state: RootWatchState,
+    mode: Extract<RootWatchMode, { kind: 'ancestor' }>,
+  ): Promise<void> {
+    let current: RootWatchMode
+    try {
+      current = await resolveRootWatchMode(state.root.path)
+    } catch (error) {
+      /* v8 ignore start -- Non-absence stat failures need a platform permission or I/O fault. */
+      if (!this.closing && state.owners.size > 0) this.handleWatcherError(state, error)
+      return
+      /* v8 ignore stop */
+    }
+    if (this.closing || state.owners.size === 0 || sameWatchMode(mode, current)) return
+    this.queueInvalidation()
+    state.unhealthy = true
+    this.scheduleRewatch(state)
+  }
+
   private async openRootWatcher(state: RootWatchState, mode: Extract<RootWatchMode, { kind: 'root' }>): Promise<WatchHandle> {
     const watcher = chokidar.watch(mode.anchor, {
       persistent: false,
@@ -481,13 +500,13 @@ class SkillWatchManager {
 
   private handleWatchEvent(
     state: RootWatchState,
-    mode: RootWatchMode,
+    mode: Extract<RootWatchMode, { kind: 'root' }>,
     event: SkillWatchEvent,
     path: string,
   ): void {
     if (this.closing || !isRelevantWatchEvent(state.root, mode, event, resolve(path))) return
     this.queueInvalidation()
-    if (mode.kind === 'ancestor' || (resolve(path) === state.root.path && event === 'unlinkDir')) {
+    if (resolve(path) === state.root.path && event === 'unlinkDir') {
       state.unhealthy = true
       this.scheduleRewatch(state)
     }
@@ -591,13 +610,10 @@ function sameWatchMode(left: RootWatchMode, right: RootWatchMode): boolean {
 
 function isRelevantWatchEvent(
   root: SkillRoot,
-  mode: RootWatchMode,
+  mode: Extract<RootWatchMode, { kind: 'root' }>,
   event: SkillWatchEvent,
   path: string,
 ): boolean {
-  if (mode.kind === 'ancestor') {
-    return path === mode.nextPath
-  }
   const segments = containedSegments(root.path, path)
   if (segments === undefined) return false
   if (segments.length === 0) return event === 'addDir' || event === 'unlinkDir'
diff --git a/packages/skill/skill-local/tests/skill-local-watcher.spec.ts b/packages/skill/skill-local/tests/skill-local-watcher.spec.ts
index 97ab8c9ee7..2a7a3e5f86 100644
--- a/packages/skill/skill-local/tests/skill-local-watcher.spec.ts
+++ b/packages/skill/skill-local/tests/skill-local-watcher.spec.ts
@@ -92,6 +92,31 @@ beforeEach(() => {
 })
 
 describe('skill-local watcher failures', () => {
+  it('ignores missing-path probes until the observed path actually changes', async () => {
+    const home = await tempDir('skill-watch-missing-stable')
+    const ctx = new Context()
+    await ctx.plugin(SkillService)
+    const fiber = await ctx.plugin(SkillLocal, {
+      dshHome: join(home, '.dsh'),
+      agentsHome: join(home, '.agents'),
+      watch: true,
+      watchPollIntervalMs: 10,
+    })
+    expect(await ctx.skills.snapshot()).toEqual({ skills: [], complete: true })
+    expect(watcherHarness.watchFiles).toHaveLength(2)
+    let invalidations = 0
+    ctx.on('skills/change', () => { invalidations += 1 })
+
+    for (const control of watcherHarness.watchFiles) {
+      control.listener({} as Stats, {} as Stats)
+    }
+    await settle()
+
+    expect(invalidations).toBe(0)
+    expect(watcherHarness.watchFiles).toHaveLength(2)
+    await fiber.dispose()
+  })
+
   it('marks a startup failure incomplete and retries discovery without caching it', async () => {
     const home = await tempDir('skill-watch-start-error')
     const root = join(home, '.dsh/skills')