[libcxx-commits] [libcxx] [libcxx] Still use CMake 3.31 in the CI image (PR #226749)

[Aiden Grossman via libcxx-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/226749

This ensures support with the minimum supported version rather than what 26.04 ships with by default (4.2.3).

>From 174ef04fce507a8d3ca89b14962e417e6d4ee5da Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman at google.com>
Date: Sun, 27 Sep 2026 03:39:06 +0000
Subject: [PATCH] [libcxx] Still use CMake 3.31 in the CI image

This ensures support with the minimum supported version rather than what
26.04 ships with by default (4.2.3).
---
 libcxx/utils/ci/docker/linux-builder.dockerfile | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libcxx/utils/ci/docker/linux-builder.dockerfile b/libcxx/utils/ci/docker/linux-builder.dockerfile
index 5035899cfda3c..64dde3cf00f52 100644
--- a/libcxx/utils/ci/docker/linux-builder.dockerfile
+++ b/libcxx/utils/ci/docker/linux-builder.dockerfile
@@ -134,3 +134,10 @@ RUN <<EOF
   sudo rm -rf /tmp/ce-infra
 EOF
 
+RUN <<EOF
+    # Install a recent CMake
+    set -e
+    wget https://github.com/Kitware/CMake/releases/download/v3.31.0/cmake-3.31.0-linux-x86_64.sh -O /tmp/install-cmake.sh
+    sudo bash /tmp/install-cmake.sh --prefix=/usr --exclude-subdir --skip-license
+    rm /tmp/install-cmake.sh
+EOF