.github/workflows/build-pull-request.yml

@@ -4,6 +4,10 @@ on:
   pull_request:
     types: ['opened', 'synchronize']
 
+concurrency:
+  group: ${{ github.workflow }}-pr-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   build-pull-request:
     name: Build pull request

.github/workflows/docker-pr.yml

@@ -6,6 +6,10 @@ on:
       - 'Dockerfile'
       - '.github/workflows/docker-pr.yml'
 
+concurrency:
+  group: ${{ github.workflow }}-pr-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   docker-build:
     runs-on: ubuntu-latest

.github/workflows/lockfile.yml

@@ -5,6 +5,10 @@ on:
     paths:
       - 'package-lock.json'
 
+concurrency:
+  group: ${{ github.workflow }}-pr-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   lockfile_changes:
     runs-on: ubuntu-latest

.github/workflows/rat-dev-preview.yml

@@ -4,6 +4,13 @@ on:
   push:
     branches: ['dev']
 
+# One run per ref wins: a newer push to dev cancels the older queued or running one, so the run
+# that builds rat-dev-dist is always the newest. Pull-request runs are other workflows and other
+# groups; they never cancel it.
+concurrency:
+  group: rat-dev-preview
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Build dev preview