pwsh ignores -OutputFormat text when writing to a redirected stderr stream #5912
Description
Steps to reproduce
$p = [Diagnostics.Process]::new()
$p.StartInfo.FileName = "pwsh"
$encoded = [Convert]::ToBase64String([Text.Encoding]::Unicode.GetBytes("throw 'boom'"))
$p.StartInfo.Arguments = "-EncodedCommand $encoded -ExecutionPolicy Bypass -NoLogo -NonInteractive -NoProfile -OutputFormat text"
$p.StartInfo.UseShellExecute = $false
$p.StartInfo.RedirectStandardError = $true
$p.Start() | Out-Null
$p.StandardError.ReadToEnd()Expected behavior
The error is written to stderr as text:
boom
At line:1 char:1
+ throw 'boom'
+ ~~~~~~~~~~~~
+ CategoryInfo : OperationStopped: (boom:String) [], RuntimeException
+ FullyQualifiedErrorId : boom
Changing $p.StartInfo.RedirectStandardError to $false (the default) will result in the expected output.
Actual behavior
The error record is encoded as CLIXML before being written to stderr:
#< CLIXML
<Objs Version="1.1.0.1" xmlns="http://schemas.microsoft.com/powershell/2004/04"><S S="Error">boom_x000D__x000A_</S><S S="Error">At line:1 char:1_x000D__x000A_</S><S S="Error">+ throw 'boom'_x000D__x000A_</S><S S="Error">+ ~~~~~~~~~~~~_x000D__x000A_</S><S S="Error">+ CategoryInfo : OperationStopped: (boom:String) [], RuntimeException_x000D__x000A_</S><S S="Error">+ FullyQualifiedErrorId : boom_x000D__x000A_</S><S S="Error"> _x000D__x000A_</S></Objs>
This problem doesn't seem to apply to stdout. Setting $p.StartInfo.RedirectStandardOutput = $true in a similar fashion works as expected.
Environment data
> $PSVersionTable
Name Value
---- -----
PSVersion 6.0.0
PSEdition Core
GitCommitId v6.0.0
OS Microsoft Windows 10.0.16299
Platform Win32NT
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0