[numeromancer]

> Any invocation of an external program can fail for a variety of reasons, and the shell doesn't provide adequate mechanisms for dealing with it, apart from exit codes and filtering error text output.

True, handling multiple sub-processes is difficult in most Unix shells. This is a function where Powershell could have done so much better, but didn't. It is somewhat better than bash&co, but could have been much more so. Python does it much better than Powershell does.