Using powershell call native command-line app and capture STDERR

No, alas. This ugliness is an by-design feature of Powershell :( If an application prints to standard error (and anything else is listening), then Powershell wraps each line in an obfuscating 'NativeCommandError' object. See https://stackoverflow.com/questions/1394084/ignoring-an-errorlevel-0-in-windows-powershell for more detail

You could silence the ugly objects, but then you'd lose the useful content too.

This is one solution I've found. Please post your answer if you have a better answer (this is intended only for command-line utilities that send status messages to STDERR instead of normal output stream):

PS> $output = dos2unix.exe -n StartApp.sh StartApp_fixed.sh 2>&1
$output.CategoryInfo.TargetName | Out-Default
dos2unix: converting file StartApp.sh to file StartApp_fixed.sh in UNIX format ...

I believe I've just stumbled upon a slightly cleaner solution than @yzorg's. The redirect of stdout to stderr is not enough as it's still an ErrorRecord object at this point, not a string. Instead, it needs to be processes and the following seems to extract just what's needed with a minimum of effort:

PS> dos2unix.exe -n StartApp.sh StartApp_fixed.sh 2>&1 | %{"$_"}
dos2unix: converting file StartApp.sh to file StartApp_fixed.sh in Unix format...