Add solution suggested by @fhammerl

src/Runner.Common/JobServerQueue.cs

@@ -799,7 +799,6 @@ namespace GitHub.Runner.Common
                 Trace.Verbose($"    Record: t={record.RecordType}, n={record.Name}, s={record.State}, st={record.StartTime}, {record.PercentComplete}%, ft={record.FinishTime}, r={record.Result}: {record.CurrentOperation}");
                 if (record.Issues != null)
                 {
-                    RemoveDuplicatedIssues(record);
                     foreach (var issue in record.Issues)
                     {
                         String source;
@@ -819,19 +818,6 @@ namespace GitHub.Runner.Common
 
             return mergedRecords;
         }
-
-        private void RemoveDuplicatedIssues(TimelineRecord timelineRecord)
-        {
-            Dictionary<string, Issue> issuesMap = new Dictionary<string, Issue>();
-            foreach (var i in timelineRecord.Issues)
-            {
-                issuesMap.TryAdd(i.Message, i);
-            }
-            timelineRecord.Issues.Clear();
-
-            timelineRecord.Issues.AddRange(issuesMap.Select(entry => entry.Value).ToList());
-        }
-
         private async Task UploadFile(UploadFileInfo file)
         {
             bool uploadSucceed = false;

src/Sdk/DTObjectTemplating/ObjectTemplating/TemplateContext.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
@@ -163,7 +163,6 @@ namespace GitHub.DistributedTask.ObjectTemplating
                 message = $"{prefix} {message}";
             }
 
-            Errors.Add(message);
             TraceWriter.Error(message);
         }