[llvm] [libc++][WIP] Move to Github hosted builders (PR #109720)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-github-workflow

Author: Louis Dionne (ldionne)

<details>
<summary>Changes</summary>

Libc++ experiences periodic outages of our Github actions builders, which are quite disruptive. Unfortunately, the Github self-hosted runner setup is very opaque. It works extremely well when it works, but most contributors are unable to troubleshoot issues related to the setup when they happen.

This patch attempts to move the libc++ builders to normal Github hosted runners. This is primarily to evaluate the feasibility of such a change, which would simplify our CI setup but may not scale sufficiently for our needs.

---
Full diff: https://github.com/llvm/llvm-project/pull/109720.diff


1 Files Affected:

- (modified) .github/workflows/libcxx-build-and-test.yaml (+16-16) 


``````````diff
diff --git a/.github/workflows/libcxx-build-and-test.yaml b/.github/workflows/libcxx-build-and-test.yaml
index b5e60781e00064..bdf4c1b74fdbaa 100644
--- a/.github/workflows/libcxx-build-and-test.yaml
+++ b/.github/workflows/libcxx-build-and-test.yaml
@@ -49,7 +49,13 @@ env:
 jobs:
   stage1:
     if: github.repository_owner == 'llvm'
-    runs-on: libcxx-runners-8-set
+    runs: &docker-image
+      using: 'docker'
+      image: 'libcxx/utils/ci/Dockerfile'
+      args:
+        - BASE_IMAGE: ghcr.io/actions/actions-runner:2.317.0
+        - GCC_LATEST_VERSION: 14
+        - LLVM_HEAD_VERSION: 20
     continue-on-error: false
     strategy:
       fail-fast: false
@@ -84,7 +90,8 @@ jobs:
             **/crash_diagnostics/*
   stage2:
     if: github.repository_owner == 'llvm'
-    runs-on: libcxx-runners-8-set
+    runs:
+      <<: *docker-image
     needs: [ stage1 ]
     continue-on-error: false
     strategy:
@@ -136,12 +143,15 @@ jobs:
       matrix:
         config: [
           'generic-abi-unstable',
+          'generic-asan',
+          'generic-cxx26',
           'generic-hardening-mode-debug',
           'generic-hardening-mode-extensive',
           'generic-hardening-mode-fast',
           'generic-hardening-mode-fast-with-abi-breaks',
           'generic-merged',
           'generic-modules-lsv',
+          'generic-msan',
           'generic-no-exceptions',
           'generic-no-experimental',
           'generic-no-filesystem',
@@ -155,25 +165,15 @@ jobs:
           'generic-no-rtti',
           'generic-optimized-speed',
           'generic-static',
+          'generic-tsan',
+          'generic-ubsan',
           # TODO Find a better place for the benchmark and bootstrapping builds to live. They're either very expensive
           # or don't provide much value since the benchmark run results are too noise on the bots.
           'benchmarks',
           'bootstrapping-build'
         ]
-        machine: [ 'libcxx-runners-8-set' ]
-        include:
-        - config: 'generic-cxx26'
-          machine: libcxx-runners-8-set
-        - config: 'generic-asan'
-          machine: libcxx-runners-8-set
-        - config: 'generic-tsan'
-          machine: libcxx-runners-8-set
-        - config: 'generic-ubsan'
-          machine: libcxx-runners-8-set
-        # Use a larger machine for MSAN to avoid timeout and memory allocation issues.
-        - config: 'generic-msan'
-          machine: libcxx-runners-8-set
-    runs-on: ${{ matrix.machine }}
+    runs:
+      <<: *docker-image
     steps:
       - uses: actions/checkout at v4
       - name: ${{ matrix.config }}

``````````

</details>


https://github.com/llvm/llvm-project/pull/109720