From 14a59b13c1298300dc2bdb135fa963289d6f5981 Mon Sep 17 00:00:00 2001
From: Ryan Lopopolo <rjl@hyperbo.la>
Date: Thu, 9 Sep 2021 20:20:50 -0700
Subject: [PATCH] Add GitHub Actions councurrency limits to workflows that `git
 push`

Occasionally when multiple PRs are merged to trunk quickly, the rustdoc
workflow fails due to a race between generating a new commit to push and
another workflow instance completing a push.

Limit workflow concurrency to one concurrent run per branch to ensure
pushes to trunk are processed serially.

https://github.blog/changelog/2021-04-19-github-actions-limit-workflow-run-or-job-concurrency/
---
 .github/workflows/rustdoc.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.github/workflows/rustdoc.yaml b/.github/workflows/rustdoc.yaml
index adbe5a125..e6414f27a 100644
--- a/.github/workflows/rustdoc.yaml
+++ b/.github/workflows/rustdoc.yaml
@@ -9,6 +9,8 @@ name: Documentation
       - trunk
   schedule:
     - cron: "0 0 * * WED"
+concurrency:
+  group: docs-${{ github.head_ref }}
 jobs:
   rustdoc:
     name: Build Rust API docs