add test tracing

Author: SteveL-MSFT

resources/apt/test/apt.tests.ps1

@@ -27,8 +27,8 @@ Describe 'Apt resource tests' {
             if (-not $aptExists) {
                 Set-ItResult -Skip -Because "Apt not found"
             }
-            $out = dsc config get -p $yamlPath | ConvertFrom-Json -Depth 10
-            $LASTEXITCODE | Should -Be 0
+            $out = dsc config get -p $yamlPath 2> "$TestDrive/stderr.txt" | ConvertFrom-Json -Depth 10
+            $LASTEXITCODE | Should -Be 0 -Because (Get-Content "$TestDrive/stderr.txt")
             $exists = $null -ne (Get-Command $pkgName -CommandType Application -ErrorAction Ignore)
             $observed = $out.results[1].result.actualState._exist
             $observed | Should -Be $exists