Robocopy Broken

Prerequisites

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• Make sure you are able to repro it on the latest released version
• Search the existing issues.
• Refer to the FAQ.
• Refer to Differences between Windows PowerShell 5.1 and PowerShell.

Steps to reproduce

PowerShell 7.4.0 Preview 1 Can no longer use robocopy.exe from powershell. As robocopy.exe returns status code other than 0 for successful copies.

Repro:

1. robocopy .\PowerShell-7.4.0-preview.1-win-x64\ .\temp\

Expect: Runs without creating an error object.

Actual: Creates Error Object NativeCommandExitException: Program “Robocopy.exe” ended with non-zero exit code: 1.

Issue: This will break all of our existing automation. We use robocopy everywhere. And our scripts all use ErrorAction = Stop

Expected behavior

robocopy .\PowerShell-7.4.0-preview.1-win-x64\ .\temp\

# Files are copied. No error is raised when all files are copied.

Actual behavior

robocopy .\PowerShell-7.4.0-preview.1-win-x64\ .\temp\
 # An error is raised even though robocopy detected no errors.
 # 1 indicates all files copied.

Error details

PS > Get-Error

Exception             :
    Type        : System.Management.Automation.NativeCommandExitException
    Path        : C:\Windows\system32\Robocopy.exe
    ExitCode    : 1
    ProcessId   : 17460
    ErrorRecord :
        Exception             :
            Type    : System.Management.Automation.ParentContainsErrorRecordException
            Message : Program "Robocopy.exe" ended with non-zero exit code: 1.
            HResult : -2146233087
        CategoryInfo          : NotSpecified: (:) [], ParentContainsErrorRecordException
        FullyQualifiedErrorId : ProgramExitedWithNonZeroCode
    Message     : Program "Robocopy.exe" ended with non-zero exit code: 1.
    HResult     : -2146233087
TargetObject          : C:\Windows\system32\Robocopy.exe
CategoryInfo          : NotSpecified: (C:\Windows\system32\Robocopy.exe:String) [], NativeCommandExitException
FullyQualifiedErrorId : ProgramExitedWithNonZeroCode

Environment data

$PSVersionTable

Name                           Value
----                           -----
PSVersion                      7.4.0-preview.1
PSEdition                      Core
GitCommitId                    7.4.0-preview.1
OS                             Microsoft Windows 10.0.22621
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Visuals

Steps.zip

[SteveL-MSFT]

@jazzdelightsme I believe it was mentioned in a separate issue that $PSNativeCommandUseErrorActionPreference is default to $false and only set to $true in 7.4 previews to get feedback.

[sba923]

@sba923, the current behavior is a bit counter-intuitive:

• A 2> redirection also swallows the NativeCommandExitException, because the latter is implemented as a non-terminating error and is therefore treated the same as the external program’s stderr output.

  • That a non-terminating error is emitted is also problematic for other reasons, as discussed in Native error handling: $PSNativeCommandUseErrorActionPreference = $true unexpectedly causes non-terminating, not statement-terminating errors #18368, and if it were converted to a statement-terminating one, it would no longer be swallowed.

• However, if you have $ErrorActionPreference = 'Stop' in effect, the script aborts (as intended) and the NativeCommandException surfaces (but not the native program’s stderr output, as intended).

This is indeed far from intuitive…