tools/docker: fix multi-arch build for env image

The env Docker image currently fails to build on non-x86 architectures
because it attempts to install i386 libraries that are unavailable on
arm64.
Additionally, the monolithic apt-get command causes timeouts and dpkg
errors.

Fix the build by making i386 package installation conditional on amd64
and splitting the installation into smaller, more stable steps.

While at it, remove the sudo usage (not necessary, because Docker setup
is performed as root).

1 files changed, 33 insertions, 25 deletions

diff --git a/tools/docker/env/Dockerfile b/tools/docker/env/Dockerfile
index 8a234bfdd..50a1aec9b 100644
--- a/tools/docker/env/Dockerfile
+++ b/tools/docker/env/Dockerfile
@@ -49,25 +49,33 @@ FROM debian:trixie
 
 LABEL homepage="https://github.com/google/syzkaller"
 
-RUN apt-get update --allow-releaseinfo-change
+# Install Python and core build tools.
+RUN apt-get update --allow-releaseinfo-change && \
+    DEBIAN_FRONTEND=noninteractive apt-get install -y -q --no-install-recommends \
+    python3 python-is-python3 python3-legacy-cgi git \
+    make nano unzip curl ca-certificates binutils flex bison bc libelf-dev libssl-dev
+
+# Install heavy cross-compilers.
 RUN DEBIAN_FRONTEND=noninteractive apt-get install -y -q --no-install-recommends \
-	sudo make nano unzip curl ca-certificates binutils g++ \
-	g++-arm-linux-gnueabi g++-aarch64-linux-gnu g++-powerpc64le-linux-gnu \
-	g++-mips64el-linux-gnuabi64 g++-s390x-linux-gnu g++-riscv64-linux-gnu \
-	libc6-dev-i386 libc6-dev-i386-amd64-cross lib32gcc-14-dev lib32stdc++-14-dev \
-	python3 python-is-python3 python3-legacy-cgi git \
-	# These are needed to build Linux kernel:
-	flex bison bc libelf-dev libssl-dev \
-	# qemu-user is required to run alien arch binaries in pkg/cover tests.
-	qemu-user \
-	# These are various fsck-like commands needed for prog/fsck:
-	dosfstools e2fsprogs btrfs-progs util-linux f2fs-tools jfsutils \
-	util-linux dosfstools ocfs2-tools reiserfsprogs xfsprogs erofs-utils \
-	exfatprogs gfs2-utils \
-	&& \
-	apt-get -y autoremove && \
-	apt-get clean autoclean && \
-	rm -rf /var/lib/apt/lists/{apt,dpkg,cache,log} /tmp/* /var/tmp/*
+    g++ \
+    g++-arm-linux-gnueabi g++-aarch64-linux-gnu g++-powerpc64le-linux-gnu \
+    g++-mips64el-linux-gnuabi64 g++-s390x-linux-gnu g++-riscv64-linux-gnu
+
+# Install architecture-specific packages (only for amd64).
+RUN if [ "$(dpkg --print-architecture)" = "amd64" ]; then \
+        DEBIAN_FRONTEND=noninteractive apt-get install -y -q --no-install-recommends \
+        libc6-dev-i386 libc6-dev-i386-amd64-cross lib32gcc-14-dev lib32stdc++-14-dev; \
+    fi
+
+# Install filesystem tools and qemu-user, clean up.
+RUN DEBIAN_FRONTEND=noninteractive apt-get install -y -q --no-install-recommends \
+    qemu-user \
+    dosfstools e2fsprogs btrfs-progs util-linux f2fs-tools jfsutils \
+    ocfs2-tools reiserfsprogs xfsprogs erofs-utils \
+    exfatprogs gfs2-utils && \
+    apt-get -y autoremove && \
+    apt-get clean autoclean && \
+    rm -rf /var/lib/apt/lists/{apt,dpkg,cache,log} /tmp/* /var/tmp/*
 
 # Since go 1.21 the toolchain required by go.mod is automatically downloaded.
 # There is no need to version up golang here after go.mod changes.
@@ -78,17 +86,17 @@ ENV GOMODCACHE /syzkaller/.cache/gomod
 
 # Install clang.
 RUN apt-get install -y -q gnupg apt-transport-https
-RUN curl https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /usr/share/keyrings/llvm-snapshot.gpg
+RUN curl https://apt.llvm.org/llvm-snapshot.gpg.key | tee /usr/share/keyrings/llvm-snapshot.gpg
 # It uses SHA-1 signatures which are deprecated since 2026, so we have to use trusted=yes.
-RUN echo "deb [arch=amd64,arm64 signed-by=/usr/share/keyrings/llvm-snapshot.gpg trusted=yes] http://apt.llvm.org/trixie/ llvm-toolchain-trixie-21 main" | sudo tee /etc/apt/sources.list.d/llvm-21.list
+RUN echo "deb [arch=amd64,arm64 signed-by=/usr/share/keyrings/llvm-snapshot.gpg trusted=yes] http://apt.llvm.org/trixie/ llvm-toolchain-trixie-21 main" | tee /etc/apt/sources.list.d/llvm-21.list
 RUN apt-get update --allow-releaseinfo-change
 RUN apt-get install -y -q --no-install-recommends clang-21 clang-format-21 clang-tidy-21 lld-21 llvm-21-dev libclang-cpp21-dev libclang-21-dev
 RUN apt-get install -y -q --no-install-recommends flatbuffers-compiler
-RUN sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-21 100
-RUN sudo update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-21 100
-RUN sudo update-alternatives --install /usr/bin/clang-tidy clang-tidy /usr/bin/clang-tidy-21 100
-RUN sudo update-alternatives --install /usr/bin/clang-format clang-format /usr/bin/clang-format-21 100
-RUN sudo update-alternatives --install /usr/bin/ld.lld ld.lld /usr/bin/lld-21 100
+RUN update-alternatives --install /usr/bin/clang clang /usr/bin/clang-21 100
+RUN update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-21 100
+RUN update-alternatives --install /usr/bin/clang-tidy clang-tidy /usr/bin/clang-tidy-21 100
+RUN update-alternatives --install /usr/bin/clang-format clang-format /usr/bin/clang-format-21 100
+RUN update-alternatives --install /usr/bin/ld.lld ld.lld /usr/bin/lld-21 100
 RUN apt autoremove -y -q
 
 # Install the Spanner emulator.