realpathSync.native crash on rclone mount (Z:) during activation #5906

Describe the bug
The extension fails to activate when a workspace contains an rclone mount. The crash happens in warnIfPathCaseMismatch before workspace settings are applied. This causes problems later on

To Reproduce
Add a non-flutter/dart directory to the workspace, in this case mounting using rclone:
restart vscode/antigravity

Expected behavior

Log

2026-02-12 06:20:52.307 [error] Activating extension Dart-Code.dart-code failed due to an error:
2026-02-12 06:20:52.307 [error] Error: UNKNOWN: unknown error, realpath 'Z:'
at realpathSync.native (node:fs:2848:18)
at Function.native (node:electron/js2c/node_init:2:5760)
at warnIfPathCaseMismatch (c:\Users\Erikos.antigravity\extensions\dart-code.dart-code-3.128.0-universal\out\dist\extension.js:20757:130)
at activate (c:\Users\Erikos.antigravity\extensions\dart-code.dart-code-3.128.0-universal\out\dist\extension.js:2258:52)
at async KG.n (file:///c:/Users/Erikos/AppData/Local/Programs/Antigravity/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:117:14166)
at async KG.m (file:///c:/Users/Erikos/AppData/Local/Programs/Antigravity/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:117:14129)
at async KG.l (file:///c:/Users/Erikos/AppData/Local/Programs/Antigravity/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:117:13585)

You can run the Dart: Collect Diagnostic Information command from the VS Code command palette (F1) to easily capture this information or provide it manually.

Environment: * OS: Windows mounting Ubuntu

Mount Tool: rclone (SFTP mount via WinFSP)

Extension Version: 3.128.0
vscode
Version: 1.109.2 (user setup)
Commit: 591199df409fbf59b4b52d5ad4ee0470152a9b31
Date: 2026-02-10T20:18:23.520Z
Electron: 39.3.0
ElectronBuildId: 13168319
Chromium: 142.0.7444.265
Node.js: 22.21.1
V8: 14.2.231.22-electron.0
OS: Windows_NT x64 10.0.26200
antigravity:
Antigravity Version: 1.16.5
VSCode OSS Version: 1.107.0 (user setup)
Commit: 1504c8cc4b34dbfbb4a97ebe954b3da2b5634516
Date: 2026-02-02T23:37:17.781Z
Electron: 39.2.3
Chromium: 142.0.7444.175
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Windows_NT x64 10.0.26200
Language Server CL: 864538994