src/vs/platform/files/electron-main/diskFileSystemProviderServer.ts/SessionFileWatcher/watch
class SessionFileWatcher:	override watch(req: number, resource: URI, opts: IWatchOptions): IDisposable {
		if (opts.recursive) {
			throw createFileSystemProviderError('Recursive file watching is not supported from main process for performance reasons.', FileSystemProviderErrorCode.Unavailable);
		}

		return super.watch(req, resource, opts);
	}