In the Azure Pipelines PublishSymbols task, how can I use a variable as the searchPattern parameter?

Following up on my previous question:

@leo-liu-msft's solution worked well for explicitly listing the files to be included in searchPattern.

I want to generate the search pattern dynamically, so I run a PowerShell script in the step before PublishSymbols@2. This creates a string object with all of the PDB files, and their associated DLLs and EXEs, separated by Windows newlines. The string is saved in a variable (not an output variable), which is used as the argument for searchPattern in the PublishSymbols@2 task.

    - powershell: |
  [xml]$project = Get-Content $(Pipeline.Workspace)/s/Build/abc_components.targets
  $componentCount = 0
  $databaseCount = 0
  $searchPattern = @()
  $project.Project.ItemGroup.Component | ForEach-Object {
      $componentName = $_.Include
      $database = $_.Database # This is the PDB filename
      $outputFile = $_.OutputFile # This is the EXE or DLL filename
      if (($componentName -like "abc*") -or ($componentName -like "xyz*")) {
          $componentCount += 1
          if(($database -ne "") -and ($database -match $componentName)) {
              $databaseCount += 1
              $ado = Edit-ResourceName $database #Edit-ResourceName is a function that edits the path
              $searchPattern += $ado
              $ado2 = Edit-ResourceName $outputFile #Edit-ResourceName is a function that edits the path
              $searchPattern += $ado2
          }
      }
  }
  Write-Output "Number of components: " $componentCount
  Write-Output "Number of databases:  " $databaseCount
  Write-Output "searchPattern length: " $searchPattern.Length
  $searchPattern = $searchPattern | Out-String
  Write-Output $searchPattern
  echo "##vso[task.setvariable variable=searchPattern]$searchPattern"
enabled: true
displayName: Generate searchPattern for symbol table
- task: PublishSymbols@2
  inputs:
    symbolsFolder: $(Pipeline.Workspace)/s
    searchPattern: |
      $(searchPattern)
    indexSources: false
    publishSymbols: true
    symbolServerType: TeamServices
    symbolsProduct: "ABC"
    symbolsVersion: $(major).$(minor).$(revision)
    symbolsArtifactName: "Symbols_ABC.$(major).$(minor).$(revision)_$(buildConfiguration)"
  enabled: true 
  condition: eq(variables['doPublishSymbols'], 'true')
  displayName: Create symbol table

The problem is that PublishSymbols@2 only reads and processes the first line of the $(searchPattern) variable.

I had originally tried searchPattern: $(searchPattern), all on one line, but that didn't work so I tried the pipe instead. Still didn't work.

This issue probably occurs because Azure DevOps does not support multi-line variables, so when you output a multi-line variable from PowerShell to Azure DevOps variable, the multi-line data is eliminated.

To avoid this, you can use %0D%0A as a delimiter to separate multiple lines of data:

$enter = "%0D%0A"
...
$searchPattern += $ado
$searchPattern += $enter
...