[llvm] [Github][libc] Also build arm container (PR #181497)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/181497

Some of the libc full build tests also run on AArch64 machines. We need to build an ARM container or otherwise the container fails to start and we never end up running anything.

>From 71a7698cd27c47549d6b2430cd0ae282f902721d Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman at google.com>
Date: Sat, 14 Feb 2026 18:46:16 +0000
Subject: [PATCH] [Github][libc] Also build arm container

Some of the libc full build tests also run on AArch64 machines. We need
to build an ARM container or otherwise the container fails to start and
we never end up running anything.
---
 .github/workflows/build-libc-container.yml | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/build-libc-container.yml b/.github/workflows/build-libc-container.yml
index a6a0f34860831..ab766dd8f9b9d 100644
--- a/.github/workflows/build-libc-container.yml
+++ b/.github/workflows/build-libc-container.yml
@@ -19,7 +19,12 @@ jobs:
   build-libc-container:
     name: Build libc container
     if: github.repository_owner == 'llvm'
-    runs-on: ubuntu-24.04
+    runs-on: ${{ matrix.runs-on }}
+    strategy:
+      matrix:
+        runs-on:
+          - ubuntu-24.04
+          - ubuntu-24.04-arm
     steps:
       - name: Checkout LLVM
         uses: actions/checkout at 8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1