Any particular reason not to use exists() here instead?

Not really - I believe I once learnt that the async overhead is a lot larger than doing the stat itself - but I doubt it makes any difference.

Do you prefer the async method?

This little program seems to confirm it:

import 'dart:io';

main() async {
  final s = Stopwatch()..start();
  for (var i = 0; i < 10000; i++) {
    await File('abc').exists();
  }
  print('async ${s.elapsed}');
  s.reset();
  for (var i = 0; i < 10000; i++) {
    File('abc').existsSync();
  }
  print(' sync ${s.elapsed}');
}

> dart --version
Dart SDK version: 3.6.0-271.0.dev (dev) (Mon Sep 23 21:07:16 2024 -0700) on "linux_x64"
> dart bin/exists.dart
async 0:00:00.233795
 sync 0:00:00.019898

So it seems the sync methods are ~10 times faster!

Ah right, sync operations are definitely faster at the cost of blocking the thread from handling other asynchronous work. This is probably fine in this situation since I doubt we're doing any interesting asynchronous work while we're also looking for the package_config. Thanks for checking!