[net11.0] Isolate Helix job monitor setup

Install the monitor only in its Linux job after bootstrapping the pinned SDK, so repository-wide tool restores remain compatible and the non-executable Arcade bootstrap script is invoked through bash.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: kubaflo

.config/dotnet-tools.json

@@ -16,13 +16,6 @@
       ],
       "rollForward": false
     },
-    "microsoft.dotnet.helix.jobmonitor": {
-      "version": "11.0.0-beta.26379.102",
-      "commands": [
-        "dotnet-helix-job-monitor"
-      ],
-      "rollForward": false
-    },
     "api-tools": {
       "version": "1.3.5",
       "commands": [

eng/pipelines/arcade/stage-helix-tests.yml

@@ -97,9 +97,59 @@ stages:
               SYSTEM_ACCESSTOKEN: $(System.AccessToken)
               HelixAccessToken: ${{ parameters.HelixAccessToken }}
 
-  - template: /eng/common/core-templates/job/helix-job-monitor.yml
-    parameters:
-      timeoutInMinutes: 360
-      organization: dotnet
-      repository: maui
-      helixAccessToken: ${{ parameters.HelixAccessToken }}
+  - job: HelixJobMonitor
+    displayName: Monitor Helix Jobs
+    timeoutInMinutes: 360
+    pool:
+      ${{ if eq(variables['System.TeamProject'], 'public') }}:
+        name: $(DncEngPublicBuildPool)
+        demands: ImageOverride -equals build.azurelinux.3.amd64.open
+      ${{ else }}:
+        name: $(DncEngInternalBuildPool)
+        demands: ImageOverride -equals build.azurelinux.3.amd64
+    steps:
+    - checkout: self
+      fetchDepth: 1
+
+    - bash: |
+        set -euo pipefail
+
+        toolPath="$AGENT_TEMPDIRECTORY/helix-job-monitor"
+        bash ./eng/common/dotnet.sh
+        toolVersion=$(bash ./eng/common/dotnet.sh msbuild eng/Versions.props -getProperty:MicrosoftDotNetHelixSdkPackageVersion -nologo | tail -n 1)
+        if [[ -z "$toolVersion" || "$toolVersion" =~ [[:space:]] ]]; then
+          echo "Could not read the Helix SDK package version from eng/Versions.props." >&2
+          exit 1
+        fi
+
+        bash ./eng/common/dotnet.sh tool install \
+          --tool-path "$toolPath" \
+          Microsoft.DotNet.Helix.JobMonitor \
+          --version "$toolVersion"
+
+        toolDll=$(find "$toolPath/.store" -path '*/tools/*/any/Microsoft.DotNet.Helix.JobMonitor.dll' -type f -print -quit)
+        if [ ! -f "$toolDll" ]; then
+          echo "Could not find the Helix Job Monitor DLL in '$toolPath/.store'." >&2
+          exit 1
+        fi
+
+        echo "##vso[task.setvariable variable=HelixJobMonitorDll]$toolDll"
+      displayName: Install Helix Job Monitor
+
+    - bash: |
+        set -euo pipefail
+
+        bash ./eng/common/dotnet.sh exec "$(HelixJobMonitorDll)" \
+          --helix-base-uri 'https://helix.dot.net/' \
+          --polling-interval-seconds 30 \
+          --fail-on-failed-tests true \
+          --max-wait-minutes 355 \
+          --stage-name '$(System.StageName)' \
+          --organization dotnet \
+          --repository maui \
+          --build-reason '$(Build.Reason)' \
+          --source-branch '$(Build.SourceBranch)'
+      displayName: Monitor Helix Jobs
+      env:
+        SYSTEM_ACCESSTOKEN: $(System.AccessToken)
+        HELIX_ACCESSTOKEN: ${{ parameters.HelixAccessToken }}