From 04f07a91b9ae6baa2442fc112cc2b64e8cbdcc7f Mon Sep 17 00:00:00 2001
From: Ning Sun <sunng@protonmail.com>
Date: Mon, 21 Sep 2026 02:26:49 +0000
Subject: [PATCH] ci: use mold in dev-builder (#9262)

---
 docker/dev-builder/riscv64/Dockerfile      | 15 +++++
 docker/dev-builder/ubuntu/Dockerfile       | 13 +++++
 docker/dev-builder/ubuntu/Dockerfile-20.04 | 66 ----------------------
 3 files changed, 28 insertions(+), 66 deletions(-)
 delete mode 100644 docker/dev-builder/ubuntu/Dockerfile-20.04

diff --git a/docker/dev-builder/riscv64/Dockerfile b/docker/dev-builder/riscv64/Dockerfile
index 8505fa3b49a..6ea5c5d68ee 100644
--- a/docker/dev-builder/riscv64/Dockerfile
+++ b/docker/dev-builder/riscv64/Dockerfile
@@ -11,6 +11,7 @@ RUN apt-get update && \
 # Install dependencies, including the riscv64 cross toolchain.
 RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
     libssl-dev \
+    libatomic1 \
     tzdata \
     curl \
     unzip \
@@ -40,6 +41,20 @@ RUN mv -f protoc3/bin/* /usr/local/bin/
 # contains protobuf headers under /usr/local/include.
 RUN cp -r protoc3/include/* /usr/local/include/
 
+# Install mold and make it the default linker (the equivalent of
+# rui314/setup-mold with its default options on GitHub-hosted runners) for
+# lower peak memory usage during linking. The host `ld` symlink covers
+# host-side linking (build scripts, proc macros); the riscv64 symlink covers
+# the cross target -- the cross gcc driver passes -m elf64lriscv explicitly,
+# so mold picks the right emulation.
+ARG MOLD_VERSION=2.42.1
+RUN arch="$(uname -m)" && \
+    curl -fsSL -o /tmp/mold.tar.gz https://github.com/rui314/mold/releases/download/v${MOLD_VERSION}/mold-${MOLD_VERSION}-${arch}-linux.tar.gz && \
+    tar -C /usr/local --strip-components=1 -xzf /tmp/mold.tar.gz && \
+    rm /tmp/mold.tar.gz && \
+    ln -sf /usr/local/bin/mold "$(readlink -f /usr/bin/ld)" && \
+    ln -sf /usr/local/bin/mold "$(readlink -f "$(command -v riscv64-linux-gnu-ld)")"
+
 # Silence all `safe.directory` warnings, to avoid the "detect dubious repository"
 # error when building with the repository mounted from a different user.
 RUN git config --global --add safe.directory '*'
diff --git a/docker/dev-builder/ubuntu/Dockerfile b/docker/dev-builder/ubuntu/Dockerfile
index 198797b5326..ac3e2954393 100644
--- a/docker/dev-builder/ubuntu/Dockerfile
+++ b/docker/dev-builder/ubuntu/Dockerfile
@@ -11,6 +11,7 @@ RUN apt-get update && \
 # Install dependencies.
 RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
     libssl-dev \
+    libatomic1 \
     tzdata \
     curl \
     unzip \
@@ -35,6 +36,18 @@ fi
 RUN mv protoc3/bin/* /usr/local/bin/
 RUN mv protoc3/include/* /usr/local/include/
 
+# Install mold and make it the default linker (the equivalent of
+# rui314/setup-mold with its default options on GitHub-hosted runners), so
+# every link inside this image -- binaries, test executables, build scripts,
+# proc macros -- goes through mold for lower peak memory usage. The prebuilt
+# binaries require GLIBC 2.18+.
+ARG MOLD_VERSION=2.42.1
+RUN arch="$(uname -m)" && \
+    curl -fsSL -o /tmp/mold.tar.gz https://github.com/rui314/mold/releases/download/v${MOLD_VERSION}/mold-${MOLD_VERSION}-${arch}-linux.tar.gz && \
+    tar -C /usr/local --strip-components=1 -xzf /tmp/mold.tar.gz && \
+    rm /tmp/mold.tar.gz && \
+    ln -sf /usr/local/bin/mold "$(readlink -f /usr/bin/ld)"
+
 # Silence all `safe.directory` warnings, to avoid the "detect dubious repository" error when building with submodules.
 # Disabling the safe directory check here won't pose extra security issues, because in our usage for this dev build
 # image, we use it solely on our own environment (that github action's VM, or ECS created dynamically by ourselves),
diff --git a/docker/dev-builder/ubuntu/Dockerfile-20.04 b/docker/dev-builder/ubuntu/Dockerfile-20.04
deleted file mode 100644
index d78046698c3..00000000000
--- a/docker/dev-builder/ubuntu/Dockerfile-20.04
+++ /dev/null
@@ -1,66 +0,0 @@
-FROM ubuntu:20.04
-
-# The root path under which contains all the dependencies to build this Dockerfile.
-ARG DOCKER_BUILD_ROOT=.
-
-ENV LANG en_US.utf8
-WORKDIR /greptimedb
-
-RUN apt-get update && \
-    DEBIAN_FRONTEND=noninteractive apt-get install -y software-properties-common
-# Install dependencies.
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
-    libssl-dev \
-    tzdata \
-    curl \
-    unzip \
-    ca-certificates \
-    git \
-    build-essential \
-    pkg-config
-
-ARG TARGETPLATFORM
-RUN echo "target platform: $TARGETPLATFORM"
-
-ARG PROTOBUF_VERSION=29.3
-
-# Install protobuf, because the one in the apt is too old (v3.12).
-RUN if [ "$TARGETPLATFORM" = "linux/arm64" ]; then \
-    curl -OL https://github.com/protocolbuffers/protobuf/releases/download/v${PROTOBUF_VERSION}/protoc-${PROTOBUF_VERSION}-linux-aarch_64.zip && \
-    unzip protoc-${PROTOBUF_VERSION}-linux-aarch_64.zip -d protoc3; \
-elif [ "$TARGETPLATFORM" = "linux/amd64" ]; then \
-    curl -OL https://github.com/protocolbuffers/protobuf/releases/download/v${PROTOBUF_VERSION}/protoc-${PROTOBUF_VERSION}-linux-x86_64.zip && \
-    unzip protoc-${PROTOBUF_VERSION}-linux-x86_64.zip -d protoc3; \
-fi
-RUN mv protoc3/bin/* /usr/local/bin/
-RUN mv protoc3/include/* /usr/local/include/
-
-# Silence all `safe.directory` warnings, to avoid the "detect dubious repository" error when building with submodules.
-# Disabling the safe directory check here won't pose extra security issues, because in our usage for this dev build
-# image, we use it solely on our own environment (that github action's VM, or ECS created dynamically by ourselves),
-# and the repositories are pulled from trusted sources (still us, of course). Doing so does not violate the intention
-# of the Git's addition to the "safe.directory" at the first place (see the commit message here:
-# https://github.com/git/git/commit/8959555cee7ec045958f9b6dd62e541affb7e7d9).
-# There's also another solution to this, that we add the desired submodules to the safe directory, instead of using 
-# wildcard here. However, that requires the git's config files and the submodules all owned by the very same user.
-# It's troublesome to do this since the dev build runs in Docker, which is under user "root"; while outside the Docker,
-# it can be a different user that have prepared the submodules.
-RUN git config --global --add safe.directory '*'
-
-# Install Rust.
-SHELL ["/bin/bash", "-c"]
-RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --no-modify-path --default-toolchain none -y
-ENV PATH /root/.cargo/bin/:$PATH
-
-# Install Rust toolchains.
-ARG RUST_TOOLCHAIN
-RUN rustup toolchain install ${RUST_TOOLCHAIN}
-
-# Install cargo-binstall with a specific version to adapt the current rust toolchain.
-# Note: if we use the latest version, we may encounter the following `use of unstable library feature 'io_error_downcast'` error.
-# compile from source take too long, so we use the precompiled binary instead
-COPY $DOCKER_BUILD_ROOT/docker/dev-builder/binstall/pull_binstall.sh /usr/local/bin/pull_binstall.sh
-RUN chmod +x /usr/local/bin/pull_binstall.sh && /usr/local/bin/pull_binstall.sh
-
-# Install nextest.
-RUN cargo binstall cargo-nextest --no-confirm