From f1666a1decce2c5656970a481d2cd3cac289834f Mon Sep 17 00:00:00 2001
From: Joshua Colvin <jcolvin@offchainlabs.com>
Date: Wed, 18 Mar 2026 17:28:42 -0700
Subject: [PATCH] Fix fuzz workflow YAML syntax and fuzz test panic on expected
 errors
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Fix three YAML issues in fuzz.yml: two step definitions had `uses:` as
separate list items instead of step properties, and the Slack notification
payload had a trailing comma (invalid JSON). Also fix FuzzInboxMultiplexer
which panicked on errors from Pop() — errors are expected for random input
during fuzzing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 .github/workflows/fuzz.yml         | 34 +++++++++++++++++++++++++++---
 arbstate/inbox_fuzz_test.go        |  5 +----
 changelog/jco-fix-fuzz-workflow.md |  2 ++
 3 files changed, 34 insertions(+), 7 deletions(-)
 create mode 100644 changelog/jco-fix-fuzz-workflow.md

diff --git a/.github/workflows/fuzz.yml b/.github/workflows/fuzz.yml
index 6bbcf0a06c9..454c13945fe 100644
--- a/.github/workflows/fuzz.yml
+++ b/.github/workflows/fuzz.yml
@@ -1,9 +1,11 @@
 ---
 name: Fuzz Tests
+run-name: Twice Weekly Fuzzing tests triggered from @${{ github.actor }} of ${{ github.head_ref }}
 
 on:
   workflow_dispatch:
   schedule:
+    # Run at 02:36 AM UTC on Mondays and Thursdays
     - cron: "36 2 * * 1,4"
 
 permissions:
@@ -40,12 +42,38 @@ jobs:
         include: ${{fromJson(needs.list.outputs.fuzz-tests)}}
 
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-go@v6
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup Go
+        uses: actions/setup-go@v6
         with:
           go-version-file: "go.mod"
-      - uses: shogo82148/actions-go-fuzz/run@v1
+
+      - name: Fuzz
+        uses: shogo82148/actions-go-fuzz/run@v1
         with:
           packages: ${{ matrix.package }}
           fuzz-regexp: ${{ matrix.func }}
           fuzz-time: "1m"
+
+  notify-on-failure:
+    name: Notify Slack on failure
+    needs: [fuzz]
+    runs-on: ubuntu-4
+    if: ${{ failure() }}
+    env:
+      RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
+    steps:
+      - name: Send Slack notification
+        uses: slackapi/slack-github-action@v2.1.1
+        with:
+          errors: true
+          method: chat.postMessage
+          token: ${{ secrets.SLACK_BOT_TOKEN }}
+          payload: |
+            {
+              "channel": "${{ secrets.SLACK_CHANNEL_ID }}",
+              "text": "⚠️ Fuzzing job failed! ${{ env.RUN_URL }}"
+            }
+
diff --git a/arbstate/inbox_fuzz_test.go b/arbstate/inbox_fuzz_test.go
index da67cf2af21..712044ecbc6 100644
--- a/arbstate/inbox_fuzz_test.go
+++ b/arbstate/inbox_fuzz_test.go
@@ -78,9 +78,6 @@ func FuzzInboxMultiplexer(f *testing.F) {
 			daprovider.KeysetValidate,
 			chaininfo.ArbitrumDevTestChainConfig(),
 		)
-		_, err := multiplexer.Pop(context.TODO())
-		if err != nil {
-			panic(err)
-		}
+		_, _ = multiplexer.Pop(context.TODO())
 	})
 }
diff --git a/changelog/jco-fix-fuzz-workflow.md b/changelog/jco-fix-fuzz-workflow.md
new file mode 100644
index 00000000000..81663c214f7
--- /dev/null
+++ b/changelog/jco-fix-fuzz-workflow.md
@@ -0,0 +1,2 @@
+### Ignored
+- Fix fuzz CI workflow YAML syntax errors and fix FuzzInboxMultiplexer panicking on expected errors.