From f15925ddf7b5c21340f610a441db2387afd10415 Mon Sep 17 00:00:00 2001
From: Drew Raines <drew@raines.me>
Date: Fri, 6 Mar 2026 15:50:02 -0600
Subject: [PATCH] Add concurrency group to prevent duplicate comments

Serializes workflow runs per issue so that when multiple `assigned`
events fire simultaneously, only the first run acts. Subsequent runs
see 0 assignees and exit early, preventing duplicate comments.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 .github/workflows/enforce-single-assignee.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.github/workflows/enforce-single-assignee.yaml b/.github/workflows/enforce-single-assignee.yaml
index 8058632..7ece63b 100644
--- a/.github/workflows/enforce-single-assignee.yaml
+++ b/.github/workflows/enforce-single-assignee.yaml
@@ -9,6 +9,8 @@ jobs:
   enforce:
     name: Enforce Single Assignee
     runs-on: ubuntu-latest
+    concurrency:
+      group: enforce-single-assignee-${{ github.event.issue.number }}
     permissions:
       issues: write
     steps: