Switch to using the environment variable directly in the CLI call

Author: marcpopMSFT

test/HelixTasks/SDKCustomCreateXUnitWorkItemsWithTestExclusion.cs

@@ -149,11 +149,11 @@ private async Task<List<ITaskItem>> PrepareWorkItem(ITaskItem xunitProject)
             foreach (var assemblyPartitionInfo in assemblyPartitionInfos)
             {
                 string command;
-                string logFileLocation = Path.Combine(Environment.GetEnvironmentVariable("HELIX_WORKITEM_UPLOAD_ROOT"),"dotnetTestLog.log");
+                string enableDiagLogging = IsPosixShell ? "-d $HELIX_WORKITEM_UPLOAD_ROOT//dotnetTestLog.log" : "-d %HELIX_WORKITEM_UPLOAD_ROOT%\\dotnetTestLog.log";
 
                 var testFilter = string.IsNullOrEmpty(assemblyPartitionInfo.ClassListArgumentString) ? "" : $"--filter \"{assemblyPartitionInfo.ClassListArgumentString}\"";
                 command = $"{driver} test {assemblyName} -e HELIX_WORK_ITEM_TIMEOUT={timeout} {testExecutionDirectory} {msbuildAdditionalSdkResolverFolder} " +
-                            $"{(XUnitArguments != null ? " " + XUnitArguments : "")} --results-directory .{Path.DirectorySeparatorChar} --logger trx --blame-hang --blame-hang-timeout 15m {testFilter} -d {logFileLocation} -- {arguments}";
+                            $"{(XUnitArguments != null ? " " + XUnitArguments : "")} --results-directory .{Path.DirectorySeparatorChar} --logger trx --blame-hang --blame-hang-timeout 15m {testFilter} {enableDiagLogging} -- {arguments}";
 
                 Log.LogMessage($"Creating work item with properties Identity: {assemblyName}, PayloadDirectory: {publishDirectory}, Command: {command}");