From ba2affae7ffa098b3ed2d4152f72e1d202694f66 Mon Sep 17 00:00:00 2001
From: can1357 <me@can.ac>
Date: Wed, 6 May 2026 17:23:33 +0200
Subject: [PATCH] fix(coding-agent): restore path alias equivalence

Fixes #935
---
 packages/coding-agent/src/main.ts             | 20 +++++++++----------
 .../src/task/isolation-backend.ts             |  4 ++--
 packages/utils/src/dirs.ts                    |  7 ++++++-
 packages/utils/test/issue-935-repro.test.ts   | 14 ++++++-------
 4 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/packages/coding-agent/src/main.ts b/packages/coding-agent/src/main.ts
index 2c51de11f..80b603ff6 100644
--- a/packages/coding-agent/src/main.ts
+++ b/packages/coding-agent/src/main.ts
@@ -10,7 +10,15 @@ import * as os from "node:os";
 import * as path from "node:path";
 import { createInterface } from "node:readline/promises";
 import type { ImageContent } from "@oh-my-pi/pi-ai";
-import { $env, getProjectDir, logger, postmortem, setProjectDir, VERSION } from "@oh-my-pi/pi-utils";
+import {
+	$env,
+	getProjectDir,
+	logger,
+	normalizePathForComparison,
+	postmortem,
+	setProjectDir,
+	VERSION,
+} from "@oh-my-pi/pi-utils";
 import chalk from "chalk";
 import type { Args } from "./cli/args";
 import { processFileArguments } from "./cli/file-processor";
@@ -215,11 +223,6 @@ async function runInteractiveMode(
 	}
 }
 
-function normalizePathForComparison(value: string): string {
-	const resolved = path.resolve(value);
-	return process.platform === "win32" ? resolved.toLowerCase() : resolved;
-}
-
 async function promptForkSession(session: SessionInfo): Promise<boolean> {
 	if (!process.stdin.isTTY) {
 		return false;
@@ -348,10 +351,7 @@ async function maybeAutoChdir(parsed: Args): Promise<void> {
 		return;
 	}
 
-	const normalizePath = (value: string) => {
-		const resolved = path.resolve(value);
-		return process.platform === "win32" ? resolved.toLowerCase() : resolved;
-	};
+	const normalizePath = normalizePathForComparison;
 
 	const cwd = normalizePath(getProjectDir());
 	const normalizedHome = normalizePath(home);
diff --git a/packages/coding-agent/src/task/isolation-backend.ts b/packages/coding-agent/src/task/isolation-backend.ts
index b0bac736f..e27164139 100644
--- a/packages/coding-agent/src/task/isolation-backend.ts
+++ b/packages/coding-agent/src/task/isolation-backend.ts
@@ -9,7 +9,7 @@ export interface IsolationBackendResolution {
 	warning: string;
 }
 
-type ProcessorEnv = Pick<NodeJS.ProcessEnv, "PROCESSOR_ARCHITECTURE" | "PROCESSOR_ARCHITEW6432">;
+type ProcessorEnv = Partial<Pick<NodeJS.ProcessEnv, "PROCESSOR_ARCHITECTURE" | "PROCESSOR_ARCHITEW6432">>;
 
 function isWindowsArm64HostUnderX64Emulation(
 	platform: NodeJS.Platform,
@@ -28,7 +28,7 @@ export async function resolveIsolationBackendForTaskExecution(
 	repoRoot: string | null,
 	platform: NodeJS.Platform = process.platform,
 	arch: NodeJS.Architecture = process.arch,
-	env: ProcessorEnv = process.env,
+	env: ProcessorEnv = process.env as ProcessorEnv,
 ): Promise<IsolationBackendResolution> {
 	let effectiveIsolationMode = requestedMode;
 	let warning = "";
diff --git a/packages/utils/src/dirs.ts b/packages/utils/src/dirs.ts
index 0e4bd35a6..f39c5f5f7 100644
--- a/packages/utils/src/dirs.ts
+++ b/packages/utils/src/dirs.ts
@@ -48,7 +48,12 @@ function standardizeMacOSPath(p: string): string {
 }
 
 export function resolveEquivalentPath(inputPath: string): string {
-	return path.resolve(inputPath);
+	const resolvedPath = path.resolve(inputPath);
+	try {
+		return fs.realpathSync(resolvedPath);
+	} catch {
+		return resolvedPath;
+	}
 }
 
 export function normalizePathForComparison(inputPath: string): string {
diff --git a/packages/utils/test/issue-935-repro.test.ts b/packages/utils/test/issue-935-repro.test.ts
index 9f7259944..e56132974 100644
--- a/packages/utils/test/issue-935-repro.test.ts
+++ b/packages/utils/test/issue-935-repro.test.ts
@@ -8,15 +8,15 @@ describe("issue #935 path equivalence", () => {
 		vi.restoreAllMocks();
 	});
 
-	it("preserves the lexical project path instead of canonicalizing symlink or junction targets", () => {
+	it("falls back to the lexical project path when realpath fails", () => {
 		const inputPath = path.resolve("/sessions/link-project");
-		const targetPath = path.resolve("/sessions/real-project");
-		const realpathSpy = vi.spyOn(fs, "realpathSync").mockImplementation(((p: fs.PathLike) => {
-			if (path.resolve(String(p)) === inputPath) return targetPath;
-			return path.resolve(String(p));
-		}) as typeof fs.realpathSync);
+		const realpathSpy = vi.spyOn(fs, "realpathSync").mockImplementation((() => {
+			const error = new Error("ENOENT: no such file or directory, realpath");
+			(error as NodeJS.ErrnoException).code = "ENOENT";
+			throw error;
+		}) as unknown as typeof fs.realpathSync);
 
 		expect(resolveEquivalentPath(inputPath)).toBe(inputPath);
-		expect(realpathSpy).not.toHaveBeenCalled();
+		expect(realpathSpy).toHaveBeenCalledWith(inputPath);
 	});
 });