René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Inconsistent handling of native command stderr ","articleBody":"I discovered recently that the handling of `stderr` from native commands isn't being dealt with consistently between Windows PowerShell and Windows PowerShell ISE.     \r\n\r\nSteps to reproduce\r\n------------------\r\n\r\n```powershell\r\n$errorActionPreference=\"stop\"; try { cmd /c nosuchexe } catch { 'dang!' }\r\n```\r\n\r\nActual ISE behavior (expected)\r\n-----------------\r\n\r\n```none\r\ndang!\r\n```\r\nNative commands writing to `stderr` while `$errorActionPreference=\"stop\"` generate a catchable `NativeCommandError` which encapsulates the original error message in a `ErrorRecord`.   It is easy to capture, analyze, and reword error messages in context.\r\n\r\nActual CLI behavior\r\n---------------\r\n\r\n```none\r\n'nosuchexe' is not recognized as an internal or external command,\r\noperable program or batch file.\r\n```\r\n\r\nNo `NativeCommandError` is generated, no matter how `$errorActionPreference` is set.  The `stderr` from the native command is piped straight through to the default process `stderr`.   \r\n\r\nThis behavior is a serious loss of functionality, leading some to believe that PowerShell can't distinguish between `stderr` and `stdout`.   Lots of community confusion generated because of the discrepency.   See https://stackoverflow.com/questions/44488202/powershell-streaming-output/44491420#44491420, among others.\r\n\r\nAnalysis\r\n---------\r\nThe difference isn't just the ISE, I think it is related to PowerShell remote runspaces!   The full info on the caught error record (in the ISE) demonstrates the underlying exception is a RemoteException like this:\r\n\r\n```powershell\r\nPS C:\\Users\\Burt_\u003e $errorActionPreference=\"stop\"; try { cmd /c nosuchexe } catch { Format-List * -force -InputObject $_ }\r\n\r\n\r\n\r\nPSMessageDetails      : \r\nException             : System.Management.Automation.RemoteException: 'nosuchexe' is not recognized as an internal or external \r\n                        command,\r\nTargetObject          : 'nosuchexe' is not recognized as an internal or external command,\r\nCategoryInfo          : NotSpecified: ('nosuchexe' is ...ternal command,:String) [], RemoteException\r\nFullyQualifiedErrorId : NativeCommandError\r\nErrorDetails          : \r\nInvocationInfo        : System.Management.Automation.InvocationInfo\r\nScriptStackTrace      : at \u003cScriptBlock\u003e, \u003cNo file\u003e: line 1\r\nPipelineIterationInfo : {}\r\n```\r\n\r\n\r\n\r\nEnvironment data\r\n----------------\r\nBoth powershell.exe and powershell_ise.exe report the same version information:\r\n\r\n```powershell\r\nName                           Value\r\n----                           -----\r\nPSVersion                      5.1.15063.296\r\nPSEdition                      Desktop\r\nPSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}\r\nBuildVersion                   10.0.15063.296\r\nCLRVersion                     4.0.30319.42000\r\nWSManStackVersion              3.0\r\nPSRemotingProtocolVersion      2.3\r\nSerializationVersion           1.1.0.1\r\n```\r\n","author":{"url":"https://github.com/BurtHarris","@type":"Person","name":"BurtHarris"},"datePublished":"2017-06-13T03:07:21.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":48},"url":"https://github.com/3996/PowerShell/issues/3996"}