[libcxx-commits] [libcxx] [libc++][CI] Updates Clang HEAD version in Docker. (PR #126419)

[Mark de Wever via libcxx-commits]

https://github.com/mordante created https://github.com/llvm/llvm-project/pull/126419

This is a preparation to test Clang 21 in the CI,

Drive-by: Updated some outdated documentation.

>From a31b85e04d98f9cd177f391ab38f5303edff42c8 Mon Sep 17 00:00:00 2001
From: Mark de Wever <koraq at xs4all.nl>
Date: Sun, 9 Feb 2025 15:13:36 +0100
Subject: [PATCH] [libc++][CI] Updates Clang HEAD version in Docker.

This is a preparation to test Clang 21 in the CI,

Drive-by: Updated some outdated documentation.
---
 libcxx/utils/ci/Dockerfile         | 9 ++++-----
 libcxx/utils/ci/docker-compose.yml | 2 +-
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/libcxx/utils/ci/Dockerfile b/libcxx/utils/ci/Dockerfile
index d0144908f098bd9..bd41f288686a44a 100644
--- a/libcxx/utils/ci/Dockerfile
+++ b/libcxx/utils/ci/Dockerfile
@@ -7,18 +7,17 @@
 # ===----------------------------------------------------------------------===##
 #
 # This file defines the buildkite and github actions builder images.
-# You can build both images using:
+# This images are tagged with <tag>. You can build both images using:
 #
-#   docker compose build
+#   TAG=<tag> docker compose build
 #
 # Or you can select a single image to build
 #
-#  docker compose build buildkite-builder
+#  TAG=test docker compose build actions-builder
 #
 # The final images can be found at
 #
-#  ghcr.io/libcxx/buildkite-builder
-#  ghcr.io/libcxx/actions-builder
+#  ghcr.io/libcxx/libcxx-linux-builder
 #  ghcr.io/libcxx/android-buildkite-builder
 #
 # Members of the github.com/libcxx/ organizations can push new images to the CI.
diff --git a/libcxx/utils/ci/docker-compose.yml b/libcxx/utils/ci/docker-compose.yml
index 1e5d35a7fecdb55..16db1b0e3acb30c 100644
--- a/libcxx/utils/ci/docker-compose.yml
+++ b/libcxx/utils/ci/docker-compose.yml
@@ -1,6 +1,6 @@
 x-versions: &compiler_versions
   GCC_LATEST_VERSION: 14
-  LLVM_HEAD_VERSION: 20
+  LLVM_HEAD_VERSION: 21
 
 services:
   actions-builder: