📦 alpine-glibc

Automated build and release of GNU C Library (glibc) packages for Alpine Linux.

Alpine Linux uses musl libc by default. This project provides a GitHub Actions pipeline generating multi-architecture APK packages for glibc, allowing the execution of glibc-linked binaries on Alpine — Python wheels, VS Code Server, Rust tools, etc.

✨ Features

• 🔄 Auto-Update: automatically detects and builds new versions of glibc.
• 🏗️ Multi-Arch: native support for x86_64 and aarch64 (ARM64) only.
• 🛠️ Reproducible: built in standardized Docker containers.
• 📦 Sub-packages: glibc, glibc-bin, glibc-libs, glibc-i18n, glibc-dev.
• 🔀 musl/glibc Switch: glibc-enable / glibc-disable tools included in glibc-bin.

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🚀 Fast Installation

# Downloads and installs all packages for your architecture
wget -qO- https://raw.githubusercontent.com/felix9743/alpine-glibc/main/install.sh | sh

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📋 Manual Installation

1. Identify your architecture

uname -m  # x86_64 or aarch64

2. Download and install

VERSION="2.43"
ARCH=$(uname -m)

# Download
wget https://github.com/felix9743/alpine-glibc/releases/download/v${VERSION}/glibc-${VERSION}-${ARCH}.apk
wget https://github.com/felix9743/alpine-glibc/releases/download/v${VERSION}/glibc-bin-${VERSION}-${ARCH}.apk
wget https://github.com/felix9743/alpine-glibc/releases/download/v${VERSION}/glibc-libs-${VERSION}-${ARCH}.apk

# Installation (post-install scripts automatically configure symlinks and ldconfig)
apk add --allow-untrusted glibc-${VERSION}-${ARCH}.apk glibc-bin-${VERSION}-${ARCH}.apk glibc-libs-${VERSION}-${ARCH}.apk

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📦 Package Description

Package	Description	Source
glibc	Required. Core shared libraries.	Compiled from GNU sources
glibc-bin	Utilities: ldconfig, ldd, glibc-enable, glibc-disable.	Compiled from GNU sources
glibc-libs	Runtime libs: libstdc++.so.6, libgcc_s.so.1, libtirpc.so.3.	Extracted from Debian Trixie
glibc-i18n	Localization data (locales).	Compiled from GNU sources
glibc-dev	Development headers.	Compiled from GNU sources

Why is glibc-libs separate from glibc-bin? libstdc++, libgcc_s and libtirpc are not produced by the glibc build. libtirpc replaces the deprecated Sun RPC support removed from glibc >= 2.26. All are extracted from Debian Trixie to ensure ABI compatibility with Debian binaries. If these libs are ever compiled from source, they will be integrated into glibc-bin.

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🔀 musl / glibc Switch

The glibc-bin package includes two tools to switch the system dynamic linker:

# Enable glibc as loader (automatic musl backup as .musl)
glibc-enable

# Restore musl
glibc-disable

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🔧 Post-Installation Verification

# Verify glibc loader
/usr/lib/glibc/bin/ldd --version

# Verify system symlinks
ls -la /lib64/ld-linux-x86-64.so.2    # x86_64
ls -la /lib/x86_64-linux-gnu/libc.so.6
ls -la /usr/lib/x86_64-linux-gnu/libstdc++.so.6

# Verify ldconfig cache
cat /etc/ld.so.conf.d/glibc.conf

# Test glibc-linked Python wheel
uv python install 3.12-gnu
uv run --python 3.12-gnu python -c "import sys; print(sys.version)"

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📁 Installation Structure

glibc files are installed under /usr/lib/glibc/ (FHS standard path):

/usr/lib/glibc/
├── lib/          # shared libraries (.so)
├── bin/          # utilities (ldd, locale...)
├── sbin/         # ldconfig
├── share/        # i18n data
└── etc/          # ld.so.conf, ld.so.cache

/lib64/ld-linux-x86-64.so.2              → /usr/lib/glibc/lib/ld-linux-x86-64.so.2
/lib/x86_64-linux-gnu/libc.so.6          → /usr/lib/glibc/lib/libc.so.6
/usr/lib/x86_64-linux-gnu/libstdc++.so.6 → /usr/lib/glibc/lib/libstdc++.so.6
/usr/lib/x86_64-linux-gnu/libtirpc.so.3  → /usr/lib/glibc/lib/libtirpc.so.3
/etc/ld.so.conf.d/glibc.conf

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🛠️ Manual Build (Local)

If you want to build the packages yourself without using GitHub Actions, follow these steps:

1. Prerequisites

• Docker (for the glibc compilation)
• Alpine Linux environment with abuild, bash, and curl (or an Alpine container)
• RSA keys for signing (abuild-keygen -a -i)

2. Build the glibc tarball

VERSION="2.43"
ARCH=$(uname -m)

# Build the Docker builder
docker build -f builder/Dockerfile -t glibc-builder .

# Run the build and save the tarball to the packaging directory
docker run --rm -e GLIBC_VERSION=$VERSION -e STDOUT=1 glibc-builder > packaging/glibc-${VERSION}-${ARCH}.tar.gz

3. Prepare Debian runtime libraries

You need libstdc++.so.6, libgcc_s.so.1 and libtirpc.so.3 from a Debian Trixie environment (or use a container):

# Example extraction steps:
mkdir -p pkg/usr/lib/glibc/lib
# Copy libstdc++.so.6, libgcc_s.so.1 and libtirpc.so.3 from a Debian system into pkg/usr/lib/glibc/lib/
tar -czf packaging/glibc-libs-${VERSION}-${ARCH}.tar.gz -C pkg .

4. Build APKs

cd packaging
# Ensure all source files (tarballs, scripts) are in the directory
abuild -r

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📜 Licenses

• Project: MIT License
• glibc: GNU Lesser General Public License (LGPL)
• libstdc++ / libgcc_s: GCC Runtime Library Exception (extracted from Debian Trixie)
• libtirpc: BSD 3-Clause License (extracted from Debian Trixie)