From 4dd0f8dca4e115d6a6654cf37e4ee639e875ac30 Mon Sep 17 00:00:00 2001
From: Sidharth Hariharan <sidharthhariharan@cmu.edu>
Date: Mon, 17 Aug 2026 11:23:00 -0700
Subject: [PATCH] ci: CI for PRs + concurrency

---
 .github/workflows/lean.yml | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/lean.yml b/.github/workflows/lean.yml
index 5ca2952..897e5c6 100644
--- a/.github/workflows/lean.yml
+++ b/.github/workflows/lean.yml
@@ -2,9 +2,13 @@ name: Lean
 
 on:
   push:
-    branches: ["main"]
+  pull_request:
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.ref }}  # Group runs by the ref (branch or PR)
+  cancel-in-progress: true  # Cancel any ongoing runs in the same group
+
 jobs:
   build:
     runs-on: ubuntu-latest