PowerShell mkdir alias   Set-StrictMode -Version 2. Strange bug. Why?
Set-StrictMode -Version 2
mkdir c:tmp1  # same with 'md c:tmp1'

c:tmp>powershell ".test.ps1"

The variable '$_' cannot be retrieved because it has not been set.
At line:50 char:38
+         $steppablePipeline.Process($_ <<<< )
    + CategoryInfo          : InvalidOperation: (_:Token) [], ParentContainsEr
   rorRecordException
    + FullyQualifiedErrorId : VariableIsUndefined

powershell ".test.ps1"
powershell -File ".test.ps1"

$steppablePipeline.Process($_)

if (test-path Variable:Local:_) {
        $steppablePipeline.Process($_)
    }