Allow flutter SDK binary to be a symlink

packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md

@@ -15,7 +15,7 @@ To learn more about DevTools, check out the
 
 ## General updates
 
-TODO: Remove this section if there are not any updates.
+* Fixed an issue with `dt sync` when Flutter on PATH is a symlink. [#9924](https://github.com/flutter/devtools/pull/9924)
 
 ## Inspector updates
 

tool/lib/model.dart

@@ -242,8 +242,19 @@ class FlutterSdk {
   }
 
   static FlutterSdk findFromPath(String sdkPath) {
-    if (path.basename(path.dirname(sdkPath)) == 'bin') {
-      return FlutterSdk._(path.dirname(path.dirname(sdkPath)));
+    var resolvedPath = sdkPath;
+    try {
+      resolvedPath = File(sdkPath).resolveSymbolicLinksSync();
+    } catch (_) {
+      // Fallback to the unresolved path if resolution fails.
+    }
+
+    if (path.basename(path.dirname(resolvedPath)) == 'bin') {
+      return FlutterSdk._(path.dirname(path.dirname(resolvedPath)));
+    } else if (path.basename(resolvedPath) == 'bin') {
+      return FlutterSdk._(path.dirname(resolvedPath));
+    } else if (Directory(path.join(resolvedPath, 'bin')).existsSync()) {
+      return FlutterSdk._(resolvedPath);
     }
 
     throw Exception('Unable to locate the Flutter SDK at "$sdkPath"');
@@ -258,10 +269,7 @@ class FlutterSdk {
     final result = Process.runSync(whichCommand, ['flutter']);
     if (result.exitCode == 0) {
       final sdkPath = result.stdout.toString().split('\n').first.trim();
-      // 'flutter/bin'
-      if (path.basename(path.dirname(sdkPath)) == 'bin') {
-        return FlutterSdk._(path.dirname(path.dirname(sdkPath)));
-      }
+      return findFromPath(sdkPath);
     }
 
     throw Exception('Unable to locate the Flutter SDK on PATH');

tool/test/model_test.dart

@@ -0,0 +1,61 @@
+// Copyright 2026 The Flutter Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file or at https://developers.google.com/open-source/licenses/bsd.
+
+import 'dart:io';
+
+import 'package:devtools_tool/model.dart';
+import 'package:path/path.dart' as path;
+import 'package:test/test.dart';
+
+void main() {
+  group('FlutterSdk.findFromPath', () {
+    late Directory tempDir;
+
+    setUp(() {
+      tempDir = Directory.systemTemp.createTempSync('flutter_sdk_test_');
+    });
+
+    tearDown(() {
+      tempDir.deleteSync(recursive: true);
+    });
+
+    test('finds SDK root from bin/flutter executable path', () {
+      final binDir = Directory(path.join(tempDir.path, 'bin'))..createSync();
+      final flutterExe = File(path.join(binDir.path, 'flutter'))..createSync();
+
+      final sdk = FlutterSdk.findFromPath(flutterExe.path);
+      expect(sdk.sdkPath, equals(tempDir.resolveSymbolicLinksSync()));
+    });
+
+    test('resolves symbolic links to find actual SDK root', () {
+      final sdkDir = Directory(path.join(tempDir.path, 'real_sdk'))
+        ..createSync();
+      final binDir = Directory(path.join(sdkDir.path, 'bin'))..createSync();
+      final flutterExe = File(path.join(binDir.path, 'flutter'))..createSync();
+
+      final linkDir = Directory(path.join(tempDir.path, 'symlink_bin'))
+        ..createSync();
+      final symlink = Link(path.join(linkDir.path, 'flutter'));
+      symlink.createSync(flutterExe.path);
+
+      final sdk = FlutterSdk.findFromPath(symlink.path);
+      expect(sdk.sdkPath, equals(sdkDir.resolveSymbolicLinksSync()));
+    });
+
+    test('finds SDK root when given SDK directory path directly', () {
+      final binDir = Directory(path.join(tempDir.path, 'bin'))..createSync();
+      File(path.join(binDir.path, 'flutter')).createSync();
+
+      final sdk = FlutterSdk.findFromPath(tempDir.path);
+      expect(sdk.sdkPath, equals(tempDir.resolveSymbolicLinksSync()));
+    });
+
+    test('throws Exception when unable to locate Flutter SDK', () {
+      expect(
+        () => FlutterSdk.findFromPath('/non/existent/path/to/flutter'),
+        throwsA(isA<Exception>()),
+      );
+    });
+  });
+}