[libcxx-commits] [libcxx] Rehome libcxx-builder docker image & attempt gentler termination. (PR #71604)

[Mark de Wever via libcxx-commits]

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@@ -66,8 +65,8 @@ RUN locale-gen
 # LLVM 15, we still need to have Clang 12 in this Docker image because the LLVM
 # 14 release branch CI uses it. The tip-of-trunk CI will never use Clang 12,
 # though.
-# LLVM POST-BRANCH bump version
-ENV LLVM_HEAD_VERSION=18
+ARG LLVM_HEAD_VERSION
----------------
mordante wrote:

```suggestion
ARG LLVM_HEAD_VERSION # populated in the docker-compose file
```

https://github.com/llvm/llvm-project/pull/71604