fix(cli): tolerate pre-existing plan directory on OneDrive

packages/opencode/src/kilocode/session/prompt.ts

@@ -133,6 +133,16 @@ export namespace KiloSessionPrompt {
     }
   }
 
+  /**
+   * Ensures the plan file directory exists. Pre-checks with `Filesystem.isDir`
+   * because `fs.mkdir(recursive: true)` still throws `EEXIST` on Windows
+   * OneDrive ReparsePoint directories in some Node versions (kilocode#9755).
+   */
+  export async function ensurePlanDir(dir: string) {
+    if (await Filesystem.isDir(dir)) return
+    await fs.mkdir(dir, { recursive: true })
+  }
+
   /**
    * Injects plan-specific reminders into the user message when using the plan agent.
    * Ensures the plan file directory exists and tells the agent where to write.
@@ -145,7 +155,7 @@ export namespace KiloSessionPrompt {
     if (input.agent.name !== "plan") return
     const plan = Session.plan(input.session)
     const exists = await Filesystem.exists(plan)
-    if (!exists) await fs.mkdir(path.dirname(plan), { recursive: true })
+    if (!exists) await ensurePlanDir(path.dirname(plan))
     const info = exists
       ? `A plan file already exists at ${plan}. You can read it and make incremental edits using the edit tool.`
       : `No plan file exists yet. You should create your plan at ${plan} using the write tool.`

packages/opencode/test/kilocode/ensure-plan-dir.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+import { KiloSessionPrompt } from "../../src/kilocode/session/prompt"
+import { tmpdir } from "../fixture/fixture"
+
+describe("KiloSessionPrompt.ensurePlanDir", () => {
+  test("creates a missing plan directory", async () => {
+    await using tmp = await tmpdir({})
+    const dir = path.join(tmp.path, ".kilo", "plans")
+    await KiloSessionPrompt.ensurePlanDir(dir)
+    const stat = await fs.stat(dir)
+    expect(stat.isDirectory()).toBe(true)
+  })
+
+  test("is idempotent when the directory already exists", async () => {
+    await using tmp = await tmpdir({})
+    const dir = path.join(tmp.path, ".kilo", "plans")
+    await fs.mkdir(dir, { recursive: true })
+    await expect(KiloSessionPrompt.ensurePlanDir(dir)).resolves.toBeUndefined()
+    const stat = await fs.stat(dir)
+    expect(stat.isDirectory()).toBe(true)
+  })
+
+  test("creates intermediate parent directories", async () => {
+    await using tmp = await tmpdir({})
+    const dir = path.join(tmp.path, "deep", "nested", ".kilo", "plans")
+    await KiloSessionPrompt.ensurePlanDir(dir)
+    const stat = await fs.stat(dir)
+    expect(stat.isDirectory()).toBe(true)
+  })
+})