A process with mode detachedWithStdio has a null getter for exitCode.

[grouma]

This applications throws when it shouldn't:

import 'dart:io';

void main() async {
  var process =
      await Process.start('ls', [], mode: ProcessStartMode.detachedWithStdio);
  process.exitCode.then((_) {});
}

[bkonyi]

Started looking into this and it appears that this is working as intended based on the documentation.

In particular:

If mode is ProcessStartMode.detachedWithStdio a detached process will be created where the stdin, stdout and stderr are connected. The creator can communicate with the child through these. The detached process will keep running even if these communication channels are closed. The process' exit code will not become available when it terminated.

ProcessStartMode.detached behaves similarly. Exit codes are only available when using ProcessStartMode.normal.

[grouma]

Interesting that this behavior is documented. Is this due to a technical limitation? I can't fathom why this would be the preferred behavior.

[iinozemtsev]

Just learned this in a hard (~2 hours searing for an error in my code then reading through process_patch.dart) way.

While this is nice to have a doc in Process.start, it would be also helpful to mention this fact in exitCode getter

[vanlooverenkoen]

Is there any way to know if the command failed or succeeded?