Fix #3629: resolve boulder progress from worktree plan

src/hooks/start-work/context-info-builder.ts

@@ -7,6 +7,7 @@ import {
   getPlanName,
   getPlanProgress,
   readBoulderState,
+  resolveBoulderPlanPath,
   writeBoulderState,
 } from "../../features/boulder-state"
 import { log } from "../../shared/logger"
@@ -150,7 +151,8 @@ function buildExistingSessionContext(params: {
   directory: string
 }): string {
   const { existingState, sessionId, activeAgent, worktreePath, worktreeBlock, directory } = params
-  const progress = getPlanProgress(existingState.active_plan)
+  const planPath = resolveBoulderPlanPath(directory, existingState)
+  const progress = getPlanProgress(planPath)
   if (progress.isComplete) {
     return `
 ## Previous Work Complete
@@ -186,7 +188,7 @@ Looking for new plans...`
 
 **Status**: RESUMING existing work
 **Plan**: ${existingState.plan_name}
-**Path**: ${existingState.active_plan}
+**Path**: ${planPath}
 **Progress**: ${progress.completed}/${progress.total} tasks completed
 **Sessions**: ${existingState.session_ids.length + 1} (current session appended)
 **Started**: ${existingState.started_at}
@@ -197,11 +199,16 @@ Read the plan file and continue from the first unchecked task.`
 }
 
 function shouldDiscoverPlans(
+  directory: string,
   existingState: ReturnType<typeof readBoulderState>,
   explicitPlanName: string | null,
 ): boolean {
   return (!existingState && !explicitPlanName)
-    || (existingState !== null && !explicitPlanName && getPlanProgress(existingState.active_plan).isComplete)
+    || (
+      existingState !== null
+      && !explicitPlanName
+      && getPlanProgress(resolveBoulderPlanPath(directory, existingState)).isComplete
+    )
 }
 
 function buildPlanDiscoveryContext(params: {
@@ -303,7 +310,7 @@ export function buildStartWorkContextInfo(params: {
     })
   }
 
-  if (shouldDiscoverPlans(existingState, explicitPlanName)) {
+  if (shouldDiscoverPlans(ctx.directory, existingState, explicitPlanName)) {
     return buildPlanDiscoveryContext({
       contextInfo,
       sessionId,

src/hooks/start-work/index.test.ts

@@ -2,7 +2,7 @@
 
 import { describe, expect, test, beforeEach, afterEach, spyOn } from "bun:test"
 import { existsSync, mkdirSync, rmSync, writeFileSync } from "node:fs"
-import { join } from "node:path"
+import { dirname, join } from "node:path"
 import { tmpdir } from "node:os"
 import { randomUUID } from "node:crypto"
 import { createStartWorkHook } from "./index"
@@ -1013,5 +1013,39 @@ You are starting a Sisyphus work session.
       expect(output.parts[0].text).toContain("subagent")
       expect(output.parts[0].text).not.toContain("Worktree Setup Required")
     })
+
+    test("should show worktree plan progress and path when the mirrored plan exists", async () => {
+      // given
+      const mainPlanPath = join(testDir, ".sisyphus", "plans", "resume-worktree-plan.md")
+      const worktreeDir = join(testDir, "..", `resume-worktree-${randomUUID()}`)
+      const worktreePlanPath = join(worktreeDir, ".sisyphus", "plans", "resume-worktree-plan.md")
+      mkdirSync(dirname(mainPlanPath), { recursive: true })
+      mkdirSync(dirname(worktreePlanPath), { recursive: true })
+      writeFileSync(mainPlanPath, "# Plan\n- [ ] Main repo task\n")
+      writeFileSync(worktreePlanPath, "# Plan\n- [x] Worktree task 1\n- [ ] Worktree task 2\n")
+      writeBoulderState(testDir, {
+        active_plan: mainPlanPath,
+        started_at: "2026-01-01T00:00:00Z",
+        session_ids: ["old-session"],
+        plan_name: "resume-worktree-plan",
+        worktree_path: worktreeDir,
+      })
+
+      const hook = createStartWorkHook(createMockPluginInput())
+      const output = {
+        parts: [{ type: "text", text: createStartWorkPrompt() }],
+      }
+
+      try {
+        // when
+        await hook["chat.message"]({ sessionID: "session-worktree-progress" }, output)
+
+        // then
+        expect(output.parts[0].text).toContain(worktreePlanPath)
+        expect(output.parts[0].text).toContain("1/2 tasks completed")
+      } finally {
+        rmSync(worktreeDir, { recursive: true, force: true })
+      }
+    })
   })
 })