Repository navigation
PipelineVariable throws error if variable name used exists in function definition #16155
Description
Prerequisites
- Write a descriptive title.
- 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
Sample function:
function Invoke-AddOne {
param (
[Parameter(ValueFromPipeline)]
[string[]]$Number
)
Process {
$testValue = $_ + 1
$testValue
}
}Run each command to recreate error:
1,2,3 | Invoke-AddOne -PV test # does not throw error
1,2,3 | Invoke-AddOne -PV testValue # does throw errorIf this is a matter of me writing an improper example, please let me know. I see the error mentions the use of Remove-Variable, but I've never heard of any recommendations to use Remove-Variable for custom written functions. If this the case and I just need to add Remove-Variable to my functions, then my apologies.
Expected behavior
When the function is called while supplying a -PipelineVariable value, it should work as normal, storing the pipeline value within the variable name to be used downstream in the pipeline.
PS> 1,2,3 | Invoke-AddOne -PV test | % { $test }
2
3
4Does not return any errors
Actual behavior
When a variable name that is used in the definition of the function is supplied as a -PipelineVariable variable name, it throws an error.
PS> 1,2,3 | Invoke-AddOne -PV testValue | % { $testValue }
Invoke-AddOne: Cannot remove variable testValue because the variable has been optimized and is not removable. Try using the Remove-Variable cmdlet (without any aliases), or dot-sourcing the command that you are using to remove the variable.Error details
PS> Get-Error
Exception :
Type : System.Management.Automation.SessionStateUnauthorizedAccessException
ErrorRecord :
Exception :
Type : System.Management.Automation.ParentContainsErrorRecordException
Message : Cannot remove variable testValue because the variable has been optimized and is not removable. Try using the Remove-Variable cmdlet (without any aliases), or dot-sourcing the command that you are using to remove the variable.
HResult : -2146233087
TargetObject : testValue
CategoryInfo : WriteError: (testValue:String) [], ParentContainsErrorRecordException
FullyQualifiedErrorId : VariableNotRemovableRare
ItemName : testValue
TargetSite :
Name : RemoveVariable
DeclaringType : System.Management.Automation.SessionStateScope, System.Management.Automation, Version=7.2.0.9, Culture=neutral, PublicKeyToken=31bf3856ad364e35
MemberType : Method
Module : System.Management.Automation.dll
Message : Cannot remove variable testValue because the variable has been optimized and is not removable. Try using the Remove-Variable cmdlet (without any aliases), or dot-sourcing the command that you are using to remove the variable.
Source : System.Management.Automation
HResult : -2146233087
StackTrace :
at System.Management.Automation.SessionStateScope.RemoveVariable(String name, Boolean force) in System.Management.Automation.dll:token 0x6003bdf+0x46
at System.Management.Automation.SessionStateInternal.RemoveVariable(String name, Boolean force) in System.Management.Automation.dll:token 0x6003b9d+0x2a
at System.Management.Automation.PSScriptCmdlet.RunClause(Action`1 clause, Object dollarUnderbar, Object inputToProcess) in System.Management.Automation.dll:token 0x600368b+0x125
at System.Management.Automation.PSScriptCmdlet.DoProcessRecord() in System.Management.Automation.dll:token 0x6003687+0x3b
at System.Management.Automation.CommandProcessor.ProcessRecord() in System.Management.Automation.dll:token 0x6002100+0x1ae
TargetObject : testValue
CategoryInfo : WriteError: (testValue:String) [Invoke-AddOne], SessionStateUnauthorizedAccessException
FullyQualifiedErrorId : VariableNotRemovableRare,Invoke-AddOne
InvocationInfo :
MyCommand : Invoke-AddOne
ScriptLineNumber : 1
OffsetInLine : 9
HistoryId : 10
Line : 1,2,3 | Invoke-AddOne -PV testValue | % { $testValue }
PositionMessage : At line:1 char:9
+ 1,2,3 | Invoke-AddOne -PV testValue | % { $testValue }
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
InvocationName : Invoke-AddOne
CommandOrigin : Internal
ScriptStackTrace : at <ScriptBlock>, <No file>: line 1Environment data
PS> $PSVersionTable
Name Value
---- -----
PSVersion 7.2.0-preview.9
PSEdition Core
GitCommitId 7.2.0-preview.9
OS Microsoft Windows 10.0.22000
Platform Win32NT
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0Visuals
No response
Activity
vexx32 commentedon Sep 25, 2021
/cc Dongbo Wang (@daxian-dbw) looks like there's still a case or two this error can crop up. Haven't seen this one before though.
Thanks for reporting it Chad Baldwin (@chadbaldwin)!
JamesWTruher commentedon Sep 30, 2021
WG: We are supposing that there's an attempt to remove the variable in an inappropriate scope (we think it's trying to be removed from the function scope but aren't sure). We agree that this is surprising, and needs further investigation and fixing.