test: improve ci merge queue integration tests (#3206)

.github/actions/check-any-lane-result/action.yml

@@ -0,0 +1,165 @@
+name: Check any lane result
+description: Pass when any configured matrix lane reports full success
+
+inputs:
+  github-token:
+    description: Token used to inspect jobs in the current workflow run
+    required: true
+  result-name:
+    description: Human-readable suite name used in logs and errors
+    required: true
+  job-name-prefix:
+    description: Matrix job name before the lane label
+    required: true
+  lane-labels-json:
+    description: JSON array containing all acceptable lane labels
+    required: false
+    default: '["self-hosted-linux", "self-hosted-macos"]'
+  success-step-name:
+    description: Step that proves the lane ran fully and passed
+    required: false
+    default: Report success
+  poll-interval-seconds:
+    description: Delay between workflow-job API requests
+    required: false
+    default: "30"
+
+runs:
+  using: composite
+  steps:
+    - name: Wait for any lane to pass
+      uses: actions/github-script@f28e40c7f34bde8b3046d885e986cb6290c5673b # Version 7
+      env:
+        RESULT_NAME: ${{ inputs.result-name }}
+        JOB_NAME_PREFIX: ${{ inputs.job-name-prefix }}
+        LANE_LABELS_JSON: ${{ inputs.lane-labels-json }}
+        SUCCESS_STEP_NAME: ${{ inputs.success-step-name }}
+        POLL_INTERVAL_SECONDS: ${{ inputs.poll-interval-seconds }}
+      with:
+        github-token: ${{ inputs.github-token }}
+        script: |
+          const resultName = process.env.RESULT_NAME;
+          const jobNamePrefix = process.env.JOB_NAME_PREFIX;
+          const successStepName = process.env.SUCCESS_STEP_NAME;
+
+          let laneLabels;
+          try {
+            laneLabels = JSON.parse(process.env.LANE_LABELS_JSON);
+          } catch (error) {
+            core.setFailed(`Invalid lane-labels-json: ${error.message}`);
+            return;
+          }
+
+          if (!Array.isArray(laneLabels) || laneLabels.length === 0) {
+            core.setFailed('lane-labels-json must contain at least one lane label');
+            return;
+          }
+
+          const pollIntervalSeconds = Number.parseInt(
+            process.env.POLL_INTERVAL_SECONDS,
+            10
+          );
+
+          if (
+            !Number.isFinite(pollIntervalSeconds) ||
+            pollIntervalSeconds < 5
+          ) {
+            core.setFailed('poll-interval-seconds must be at least 5');
+            return;
+          }
+
+          const laneNames = laneLabels.map(
+            label => `${jobNamePrefix} (${label})`
+          );
+
+          const laneReportedSuccess = lane =>
+            lane.status === 'completed' &&
+            lane.conclusion === 'success' &&
+            lane.steps?.some(step =>
+              step.name === successStepName &&
+              step.conclusion === 'success'
+            );
+
+          let previousState = '';
+
+          while (true) {
+            try {
+              const response =
+                await github.rest.actions.listJobsForWorkflowRun({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  run_id: context.runId,
+                  filter: 'latest',
+                  per_page: 100,
+                });
+
+              const lanes = laneNames
+                .map(name =>
+                  response.data.jobs.find(job => job.name === name)
+                )
+                .filter(Boolean);
+
+              const winner = lanes.find(laneReportedSuccess);
+
+              if (winner) {
+                core.notice(
+                  `${winner.name} passed; ${resultName} result is successful`
+                );
+                return;
+              }
+
+              if (
+                lanes.length === laneNames.length &&
+                lanes.every(lane => lane.status === 'completed')
+              ) {
+                const results = lanes
+                  .map(lane => {
+                    const reportedSuccess = lane.steps?.some(step =>
+                      step.name === successStepName &&
+                      step.conclusion === 'success'
+                    );
+
+                    return (
+                      `${lane.name}: conclusion=${lane.conclusion}, ` +
+                      `${successStepName}=${reportedSuccess ? 'success' : 'not-reported'}`
+                    );
+                  })
+                  .join(', ');
+
+                core.setFailed(
+                  `None of the ${resultName} lanes passed. ${results}`
+                );
+                return;
+              }
+
+              const state = laneNames
+                .map(name => {
+                  const lane = lanes.find(candidate => candidate.name === name);
+
+                  return (
+                    `${name}: ` +
+                    `${lane?.status ?? 'not-created'}/` +
+                    `${lane?.conclusion ?? '-'}`
+                  );
+                })
+                .join(', ');
+
+              if (state !== previousState) {
+                core.info(
+                  `Waiting for a ${resultName} lane to pass. ${state}`
+                );
+                previousState = state;
+              }
+            } catch (error) {
+              // A transient API failure should not immediately fail the
+              // required result. Retry until a lane passes, all lanes finish,
+              // or the calling job reaches its timeout.
+              core.warning(
+                `Could not inspect ${resultName} jobs; retrying: ${error.message}`
+              );
+            }
+
+            await new Promise(resolve =>
+              setTimeout(resolve, pollIntervalSeconds * 1_000)
+            );
+          }

.github/actions/check-peer-success/action.yml

@@ -0,0 +1,64 @@
+name: Check peer success
+description: Stop this lane cooperatively when its peer has fully passed
+
+inputs:
+  github-token:
+    description: Token used to inspect jobs in the current workflow run
+    required: true
+  current-label:
+    description: Label identifying the current matrix lane
+    required: true
+  peer-label:
+    description: Label identifying the other matrix lane
+    required: true
+  job-name-prefix:
+    description: Job name before the matrix label
+    required: true
+
+runs:
+  using: composite
+  steps:
+    - name: Check whether peer lane passed
+      uses: actions/github-script@f28e40c7f34bde8b3046d885e986cb6290c5673b # Version 7
+      env:
+        CURRENT_LABEL: ${{ inputs.current-label }}
+        PEER_LABEL: ${{ inputs.peer-label }}
+        JOB_NAME_PREFIX: ${{ inputs.job-name-prefix }}
+      with:
+        github-token: ${{ inputs.github-token }}
+        script: |
+          const currentLabel = process.env.CURRENT_LABEL;
+          const peerLabel = process.env.PEER_LABEL;
+          const peerName = `${process.env.JOB_NAME_PREFIX} (${peerLabel})`;
+
+          try {
+            const response = await github.rest.actions.listJobsForWorkflowRun({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              run_id: context.runId,
+              filter: 'latest',
+              per_page: 100,
+            });
+
+            const peer = response.data.jobs.find(job => job.name === peerName);
+
+            const peerReportedSuccess =
+              peer?.status === 'completed' &&
+              peer?.conclusion === 'success' &&
+              peer.steps?.some(step =>
+                step.name === 'Report success' &&
+                step.conclusion === 'success'
+              );
+
+            if (peerReportedSuccess) {
+              core.notice(
+                `${peerName} passed; skipping the remaining work on ${currentLabel}`
+              );
+              core.exportVariable('PEER_SUCCEEDED', 'true');
+            }
+          } catch (error) {
+            // Coordination failure must not fail the test lane.
+            core.warning(
+              `Could not check peer job; continuing this lane: ${error.message}`
+            );
+          }

.github/workflows/cucumber-integration-tests.yml

@@ -16,7 +16,7 @@ concurrency:
 
 jobs:
   tests:
-    name: Run cucumber integration tests
+    name: Run cucumber integration tests (${{ matrix.platform.label }})
     # Heavy, self-hosted suite: run ONLY inside the merge queue so the pull
     # request phase reports only the lightweight `Cucumber result` check below.
     if: ${{ github.event_name == 'merge_group' }}
@@ -26,29 +26,25 @@ jobs:
       actions: write
       checks: write
 
-    # Each OS reports its own result so `cucumber-result` below can require
-    # that at least one OS passed. A failed run never reaches the reporting
-    # step, leaving its output empty.
-    outputs:
-      self-hosted-linux: ${{ steps.report.outputs.self-hosted-linux }}
-      self-hosted-macos: ${{ steps.report.outputs.self-hosted-macos }}
-
     strategy:
-      # All OSes should be tested even if one fails (default: true)
+      # A failed OS must not cancel the other OS because only one OS needs to pass.
       fail-fast: false
       matrix:
         platform:
           # Using self-hosted runners because we were running out of memory on GitHub-hosted runners
           - os: [ self-hosted, Linux ]
             label: self-hosted-linux
+            peer_label: self-hosted-macos
           - os: [ self-hosted, macOS ]
             label: self-hosted-macos
+            peer_label: self-hosted-linux
     runs-on: ${{ matrix.platform.os }}
     env:
       # Heavy Rust integration tests become less stable when oversubscribing the
       # self-hosted runners. Keep these lanes single-job to reduce retries.
       E2E_NEXTEST_JOBS: 1
       LOGOS_BLOCKCHAIN_NODE_BIN: ${{ github.workspace }}/target/release/logos-blockchain-node
+      PEER_SUCCEEDED: "false"
 
     steps:
       # Remove any rustup override to ensure default toolchain is used
@@ -81,9 +77,23 @@ jobs:
         id: verify_local_ntp
         uses: ./.github/actions/verify-local-ntp-server
 
+      # This cooperative checkpoint is reused before each expensive phase.
+      # It does not cancel the workflow. If the other OS has completed the
+      # entire lane and its `Report success` step passed, this lane skips all
+      # remaining expensive work and proceeds to cleanup.
+      - &check_peer_success
+        name: Stop if another Cucumber OS has already passed
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' }}
+        uses: ./.github/actions/check-peer-success
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          current-label: ${{ matrix.platform.label }}
+          peer-label: ${{ matrix.platform.peer_label }}
+          job-name-prefix: Run cucumber integration tests
+
       # Build release binaries for the cucumber tests.
       - name: Build binaries for cucumber tests
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         uses: actions-rs/cargo@9e120dd99b0fbad1c065f686657e914e76bd7b72
         with:
           command: build
@@ -91,6 +101,8 @@ jobs:
         env:
           CARGO_INCREMENTAL: 0  # Disable incremental compilation
 
+      - *check_peer_success
+
       # Run cucumber integration tests with environment variables for binaries and test params
       # Special exclusion tags (we want to run the rest of the tests and not fail the workflow):
       # - @broken = tests that are broken and must still be fixed
@@ -98,7 +110,7 @@ jobs:
 
       # Feature: Smoke (@smoke_ci)
       - name: Run cucumber suite - smoke
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         timeout-minutes: 60
         uses: ./.github/actions/run-cucumber-suite
         with:
@@ -107,9 +119,11 @@ jobs:
           artifact_subdir: Smoke
           max_concurrent_scenarios: "1"
 
+      - *check_peer_success
+
       # Feature: Cryptarchia (@cryptarchia_ci)
       - name: Run cucumber suite - cryptarchia
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         timeout-minutes: 60
         uses: ./.github/actions/run-cucumber-suite
         with:
@@ -118,9 +132,11 @@ jobs:
           artifact_subdir: Cryptarchia
           max_concurrent_scenarios: "1"
 
+      - *check_peer_success
+
       # Feature: Blend (@blend_ci)
       - name: Run cucumber suite - blend
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         timeout-minutes: 60
         uses: ./.github/actions/run-cucumber-suite
         with:
@@ -129,9 +145,11 @@ jobs:
           artifact_subdir: Blend
           max_concurrent_scenarios: "1"
 
+      - *check_peer_success
+
       # Feature: Transactions (@transactions_ci)
       - name: Run cucumber suite - transactions
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         timeout-minutes: 120
         uses: ./.github/actions/run-cucumber-suite
         with:
@@ -141,9 +159,11 @@ jobs:
           verbose_console: "true"
           max_concurrent_scenarios: "1"
 
+      - *check_peer_success
+
       # Feature: Mempool (@mempool_ci)
       - name: Run cucumber suite - mempool
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         timeout-minutes: 60
         uses: ./.github/actions/run-cucumber-suite
         with:
@@ -152,9 +172,11 @@ jobs:
           artifact_subdir: Mempool lifecycle
           verbose_console: "true"
 
+      - *check_peer_success
+
       # Feature: Zone SDK (@zone_ci)
       - name: Run cucumber suite - zone
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         timeout-minutes: 60
         uses: ./.github/actions/run-cucumber-suite
         with:
@@ -163,9 +185,11 @@ jobs:
           artifact_subdir: Zone
           max_concurrent_scenarios: "1"
 
+      - *check_peer_success
+
       # Feature: CLI utility binary (@cli_ci)
       - name: Run cucumber suite - CLI utilities
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         timeout-minutes: 60
         uses: ./.github/actions/run-cucumber-suite
         with:
@@ -174,23 +198,23 @@ jobs:
           artifact_subdir: Cli
           max_concurrent_scenarios: "1"
 
-      # Always upload JUnit test results for reporting, even if tests fail
+      # Upload JUnit test results only for a lane that ran to completion.
       - name: Upload cucumber JUnit results
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         continue-on-error: true
-        uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47 # v4.6.2
+        uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47 # Version 4.6.2
         with:
-          name: cucumber-junit-${{ runner.os }}  # ✅ Unique per OS
+          name: cucumber-junit-${{ runner.os }}
           path: ${{ github.workspace }}/tests/cucumber_tests/temp/cucumber-output-junit.xml
           if-no-files-found: warn
 
-      # Always publish a test report for visibility, do not fail workflow if this step fails
+      # Publish a test report only for a lane that ran to completion.
       - name: Publish cucumber test report
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         continue-on-error: true
         uses: dorny/test-reporter@v1
         with:
-          name: Cucumber-${{ runner.os }}  # Optional: distinguish Linux vs macOS
+          name: Cucumber-${{ runner.os }}
           path: ${{ github.workspace }}/tests/cucumber_tests/temp/cucumber-output-junit.xml
           reporter: java-junit
 
@@ -204,33 +228,50 @@ jobs:
         if: success() || failure()
         run: rm -rf ${{ github.workspace }}/tests/cucumber_tests/temp/cucumber_artefacts
 
-      # Runs only if every step above succeeded (default `if: success()`),
-      # marking this OS as passed for the `cucumber-result` job.
+      # This step is the unambiguous signal consumed by the peer lane and the
+      # required result job. A cooperatively stopped lane skips this step.
       - name: Report success
-        id: report
-        run: echo "${{ matrix.platform.label }}=success" >> "$GITHUB_OUTPUT"
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' }}
+        run: echo "All Cucumber tests passed on ${{ matrix.platform.label }}"
 
   # This is the stable required check for the Cucumber suite.
-  # On pull requests it succeeds without starting either self-hosted runner.
-  # In the merge queue it passes if at least one OS passed, so a single flaky
-  # OS run does not eject the PR. Both OS runs still execute and remain visible.
+  #
+  # It intentionally has no `needs: tests`: on merge_group it starts alongside
+  # the matrix and polls the current workflow run. It succeeds as soon as either
+  # OS has completed the entire lane and its `Report success` step passed.
+  # It fails once both lanes have completed without reporting success.
+  #
+  # On pull requests it succeeds immediately without starting self-hosted jobs.
   cucumber-result:
     name: Cucumber result
-    needs: tests
     if: ${{ !cancelled() }}
     runs-on: ubuntu-latest
+    timeout-minutes: 230
+    permissions:
+      actions: read
+      contents: read
     steps:
+      # On pull requests, report the required check without running or checking
+      # either self-hosted lane.
+      - name: Report pull-request result
+        if: ${{ github.event_name != 'merge_group' }}
+        run: echo "Cucumber integration tests run only in the merge queue"
+
+      # A local composite action must be checked out before it can be invoked.
+      # Only the required action directory is fetched.
+      - name: Checkout result action
+        if: ${{ github.event_name == 'merge_group' }}
+        uses: actions/checkout@85e6279cec87321a52edac9c87bce653a07cf6c2 # Version 4.2.2
+        with:
+          ref: ${{ github.sha }}
+          sparse-checkout: .github/actions/check-any-lane-result
+          sparse-checkout-cone-mode: false
+
       - name: Check Cucumber result
-        run: |
-          if [ "${{ github.event_name }}" != "merge_group" ]; then
-            echo "Cucumber runs only in the merge queue"
-            exit 0
-          fi
-
-          if [ "${{ needs.tests.outputs.self-hosted-linux }}" = "success" ] || \
-             [ "${{ needs.tests.outputs.self-hosted-macos }}" = "success" ]; then
-            exit 0
-          fi
-
-          echo "Both Cucumber OS runs failed"
-          exit 1
+        if: ${{ github.event_name == 'merge_group' }}
+        uses: ./.github/actions/check-any-lane-result
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          result-name: Cucumber
+          job-name-prefix: Run cucumber integration tests
+          lane-labels-json: '["self-hosted-linux", "self-hosted-macos"]'

.github/workflows/end-to-end-integration-tests.yml

@@ -16,7 +16,7 @@ concurrency:
 
 jobs:
   tests:
-    name: Run end-to-end integration tests
+    name: Run end-to-end integration tests (${{ matrix.platform.label }})
     # Heavy, self-hosted suite: run ONLY inside the merge queue so the pull
     # request phase reports only the lightweight `E2E result` check below.
     if: ${{ github.event_name == 'merge_group' }}
@@ -26,29 +26,25 @@ jobs:
       actions: write
       checks: write
 
-    # Each OS reports its own result so `e2e-result` below can require that at
-    # least one OS passed. A failed run never reaches the reporting step,
-    # leaving its output empty.
-    outputs:
-      self-hosted-linux: ${{ steps.report.outputs.self-hosted-linux }}
-      self-hosted-macos: ${{ steps.report.outputs.self-hosted-macos }}
-
     strategy:
-      # All OSes should be tested even if one fails (default: true)
+      # A failed OS must not cancel the other OS because only one OS needs to pass.
       fail-fast: false
       matrix:
         platform:
           # Using self-hosted runners because we were running out of memory on GitHub-hosted runners
           - os: [ self-hosted, Linux ]
             label: self-hosted-linux
+            peer_label: self-hosted-macos
           - os: [ self-hosted, macOS ]
             label: self-hosted-macos
+            peer_label: self-hosted-linux
     runs-on: ${{ matrix.platform.os }}
     env:
       # Heavy Rust e2e tests become less stable when nextest oversubscribes the
       # self-hosted runners. Keep these lanes single-job to reduce retries.
       E2E_NEXTEST_JOBS: 1
       LOGOS_BLOCKCHAIN_NODE_BIN: ${{ github.workspace }}/target/release/logos-blockchain-node
+      PEER_SUCCEEDED: "false"
 
     steps:
       # Remove any rustup override to ensure default toolchain is used
@@ -86,9 +82,23 @@ jobs:
         id: verify_local_ntp
         uses: ./.github/actions/verify-local-ntp-server
 
+      # This cooperative checkpoint is reused before each expensive phase.
+      # It does not cancel the workflow. If the other OS has completed the
+      # entire lane and its `Report success` step passed, this lane skips all
+      # remaining expensive work and proceeds to cleanup.
+      - &check_peer_success
+        name: Stop if another E2E OS has already passed
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' }}
+        uses: ./.github/actions/check-peer-success
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          current-label: ${{ matrix.platform.label }}
+          peer-label: ${{ matrix.platform.peer_label }}
+          job-name-prefix: Run end-to-end integration tests
+
       # Build the testing-featured node binary required by mantle_sdp.
       - name: Build testing binary for mantle_sdp
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         uses: actions-rs/cargo@9e120dd99b0fbad1c065f686657e914e76bd7b72
         with:
           command: build
@@ -96,10 +106,12 @@ jobs:
         env:
           CARGO_INCREMENTAL: 0  # Disable incremental compilation
 
+      - *check_peer_success
+
       # Run the isolated SDP ops target that requires the testing-featured node binary.
       - name: End-to-end integration tests - mantle_sdp
         id: mantle_sdp_end_to_end
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         timeout-minutes: 90
         uses: actions-rs/cargo@9e120dd99b0fbad1c065f686657e914e76bd7b72  # Version 1.0.1
         env:
@@ -108,9 +120,11 @@ jobs:
           command: nextest
           args: run --locked --jobs ${{ env.E2E_NEXTEST_JOBS }} --retries 2 -p logos-blockchain-tests --features mantle_sdp --test test_mantle_sdp_ops --test test_mantle_sdp_blend --no-fail-fast
 
+      - *check_peer_success
+
       # Build the testing-featured node binary required by tip_poll_self_heal.
       - name: Build testing binary for tip_poll_self_heal
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         uses: actions-rs/cargo@9e120dd99b0fbad1c065f686657e914e76bd7b72
         with:
           command: build
@@ -118,10 +132,12 @@ jobs:
         env:
           CARGO_INCREMENTAL: 0  # Disable incremental compilation
 
+      - *check_peer_success
+
       # Run the isolated tip-poll self-heal test that requires the testing-featured node binary.
       - name: End-to-end integration tests - tip_poll_self_heal
         id: tip_poll_self_heal_end_to_end
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         timeout-minutes: 90
         uses: actions-rs/cargo@9e120dd99b0fbad1c065f686657e914e76bd7b72  # Version 1.0.1
         env:
@@ -130,9 +146,11 @@ jobs:
           command: nextest
           args: run --locked --jobs ${{ env.E2E_NEXTEST_JOBS }} --retries 2 -p logos-blockchain-tests --features tip_poll_self_heal --test test_cryptarchia_tip_poll_self_heal --no-fail-fast
 
+      - *check_peer_success
+
       # Build release binaries for the remaining end-to-end tests.
       - name: Build binaries for remaining end-to-end tests
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         uses: actions-rs/cargo@9e120dd99b0fbad1c065f686657e914e76bd7b72
         with:
           command: build
@@ -140,17 +158,20 @@ jobs:
         env:
           CARGO_INCREMENTAL: 0  # Disable incremental compilation
 
+      - *check_peer_success
+
       # Run the remaining end-to-end integration tests using cargo-nextest for better performance and reliability
       - name: End-to-end integration tests
         id: end_to_end
-        if: ${{ success() && steps.verify_local_ntp.conclusion == 'success' }}
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' && steps.verify_local_ntp.conclusion == 'success' }}
         timeout-minutes: 90
         uses: actions-rs/cargo@9e120dd99b0fbad1c065f686657e914e76bd7b72  # Version 1.0.1
         env:
           USE_LOCAL_HOST_NTP_TIME_CONFIG: true # Ensure tests use local NTP server for time sync
         with:
           command: nextest
-          # - We don't test benches as they take 6h+, leading to a timeout
+          # We keep `--no-fail-fast` so a running nextest phase can report
+          # multiple failures before the lane concludes.
           args: run --locked --jobs ${{ env.E2E_NEXTEST_JOBS }} --retries 2 -p logos-blockchain-tests --no-fail-fast
 
       - name: Upload integration tests results on failure
@@ -168,33 +189,50 @@ jobs:
         with:
           command: clean
 
-      # Runs only if every step above succeeded (default `if: success()`),
-      # marking this OS as passed for the `e2e-result` job.
+      # This step is the unambiguous signal consumed by the peer lane and the
+      # required result job. A cooperatively stopped lane skips this step.
       - name: Report success
-        id: report
-        run: echo "${{ matrix.platform.label }}=success" >> "$GITHUB_OUTPUT"
+        if: ${{ success() && env.PEER_SUCCEEDED != 'true' }}
+        run: echo "All E2E tests passed on ${{ matrix.platform.label }}"
 
-  # This is the stable required check for the end-to-end suite.
-  # On pull requests it succeeds without starting either self-hosted runner.
-  # In the merge queue it passes if at least one OS passed, so a single flaky
-  # OS run does not eject the PR. Both OS runs still execute and remain visible.
+  # This is the stable required check for the E2E suite.
+  #
+  # It intentionally has no `needs: tests`: on merge_group it starts alongside
+  # the matrix and polls the current workflow run. It succeeds as soon as either
+  # OS has completed the entire lane and its `Report success` step passed.
+  # It fails once both lanes have completed without reporting success.
+  #
+  # On pull requests it succeeds immediately without starting self-hosted jobs.
   e2e-result:
     name: E2E result
-    needs: tests
     if: ${{ !cancelled() }}
     runs-on: ubuntu-latest
+    timeout-minutes: 230
+    permissions:
+      actions: read
+      contents: read
     steps:
+      # On pull requests, report the required check without running or checking
+      # either self-hosted lane.
+      - name: Report pull-request result
+        if: ${{ github.event_name != 'merge_group' }}
+        run: echo "End-to-end integration tests run only in the merge queue"
+
+      # A local composite action must be checked out before it can be invoked.
+      # Only the required action directory is fetched.
+      - name: Checkout result action
+        if: ${{ github.event_name == 'merge_group' }}
+        uses: actions/checkout@85e6279cec87321a52edac9c87bce653a07cf6c2 # Version 4.2.2
+        with:
+          ref: ${{ github.sha }}
+          sparse-checkout: .github/actions/check-any-lane-result
+          sparse-checkout-cone-mode: false
+
       - name: Check E2E result
-        run: |
-          if [ "${{ github.event_name }}" != "merge_group" ]; then
-            echo "End-to-end integration tests run only in the merge queue"
-            exit 0
-          fi
-
-          if [ "${{ needs.tests.outputs.self-hosted-linux }}" = "success" ] || \
-             [ "${{ needs.tests.outputs.self-hosted-macos }}" = "success" ]; then
-            exit 0
-          fi
-
-          echo "Both end-to-end OS runs failed"
-          exit 1
+        if: ${{ github.event_name == 'merge_group' }}
+        uses: ./.github/actions/check-any-lane-result
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          result-name: E2E
+          job-name-prefix: Run end-to-end integration tests
+          lane-labels-json: '["self-hosted-linux", "self-hosted-macos"]'