Publish each test assembly's results as its own CI run instead of merging

azure-pipelines-PR.yml

@@ -269,7 +269,10 @@ stages:
             inputs:
               testResultsFormat: 'XUnit'
               testRunTitle: WindowsNoRealsig_testCoreclr
-              mergeTestResults: true
+              # See eng/templates/batched-test-steps.yml: merging disjoint per-assembly XUnit
+              # files produces tens of thousands of "No matching test case result" warnings and
+              # can abort the publish, dropping results. Publish each file as its own run.
+              mergeTestResults: false
               testResultsFiles: '*.xml'
               searchFolder: '$(Build.SourcesDirectory)/artifacts/TestResults/Release'
             condition: succeededOrFailed()
@@ -375,7 +378,10 @@ stages:
             inputs:
               testResultsFormat: 'XUnit'
               testRunTitle: WindowsCompressedMetadata $(_testKind) $(transparentCompiler)
-              mergeTestResults: true
+              # See eng/templates/batched-test-steps.yml: publish each assembly file as its own
+              # run to avoid the merge-time "No matching test case result" warning flood and the
+              # "TestCaseTitle must be specified" abort that silently drops results.
+              mergeTestResults: false
               testResultsFiles: '*.xml'
               searchFolder: '$(Build.SourcesDirectory)/artifacts/TestResults/$(_configuration)'
             continueOnError: true
@@ -465,8 +471,14 @@ stages:
           - pwsh: .\eng\MockBuild.ps1
             displayName: Build with OfficialBuildId
 
-        # Linux
+        # Linux (split into 2 batches to limit test-process memory; batch 3 is desktop-only)
         - job: Linux
+          strategy:
+            matrix:
+              Batch1:
+                batchNumber: 1
+              Batch2:
+                batchNumber: 2
           pool:
             name: $(DncEngPublicBuildPool)
             demands: ImageOverride -equals $(LinuxMachineQueueName)
@@ -477,30 +489,33 @@ stages:
           steps:
           - checkout: self
             clean: true
-          - script: ./eng/cibuild.sh --configuration $(_BuildConfig) --testcoreclr --mt true
+          - script: ./eng/cibuild.sh --configuration $(_BuildConfig) --testcoreclrbatch $(batchNumber) --mt true
             displayName: Build / Test
           - script: ./eng/common/dotnet.sh fsi tests/EndToEndBuildTests/MultithreadedTasks/run.fsx -- --configuration $(_BuildConfig) --repetitions 3
             displayName: Real SDK MP / MT integration
           - task: PublishPipelineArtifact@1
             condition: always()
             inputs:
               targetPath: '$(Build.SourcesDirectory)/artifacts/MultithreadedTasks'
-              artifact: Linux SDK MT evidence
+              artifact: Linux Batch$(batchNumber) SDK MT evidence
           - task: PublishTestResults@2
             displayName: Publish Test Results
             inputs:
               testResultsFormat: 'XUnit'
-              testRunTitle: Linux
+              testRunTitle: Linux Batch$(batchNumber)
               testResultsFiles: '*.xml'
-              mergeTestResults: true
+              # See eng/templates/batched-test-steps.yml: publish each assembly file as its own
+              # run to avoid the merge-time "No matching test case result" warning flood and the
+              # "TestCaseTitle must be specified" abort that silently drops results.
+              mergeTestResults: false
               searchFolder: '$(Build.SourcesDirectory)/artifacts/TestResults/$(_BuildConfig)'
             continueOnError: true
             condition: succeededOrFailed()
           - task: PublishBuildArtifacts@1
             displayName: Publish Test Logs
             inputs:
               PathtoPublish: '$(Build.SourcesDirectory)/artifacts/TestResults/$(_BuildConfig)'
-              ArtifactName: 'Linux $(_BuildConfig) test logs'
+              ArtifactName: 'Linux $(_BuildConfig) Batch$(batchNumber) test logs'
               publishLocation: Container
             continueOnError: true
             condition: failed()
@@ -511,7 +526,7 @@ stages:
             displayName: Publish NuGet cache contents
             inputs:
               PathtoPublish: '$(Build.SourcesDirectory)/artifacts/NugetPackageRootContents'
-              ArtifactName: 'NuGetPackageContents Linux'
+              ArtifactName: 'NuGetPackageContents Linux Batch$(batchNumber)'
               publishLocation: Container
             continueOnError: true
             condition: failed()

eng/templates/batched-test-steps.yml

@@ -38,7 +38,12 @@ steps:
   inputs:
     testResultsFormat: 'XUnit'
     testRunTitle: ${{ parameters.testRunTitlePrefix }} Batch$(batchNumber)
-    mergeTestResults: true
+    # Publish each assembly's result file as its own run. Merging disjoint per-assembly
+    # XUnit files into one run makes the ADO publisher emit a "No matching test case result
+    # found on server" warning for every test in every file after the first (tens of thousands
+    # of warnings per build), and can abort with "TestCaseTitle must be specified", silently
+    # dropping a whole assembly's results.
+    mergeTestResults: false
     testResultsFiles: '*.xml'
     searchFolder: '$(Build.SourcesDirectory)/artifacts/TestResults/${{ parameters.configuration }}'
   continueOnError: true