name: Setup musl 1.2.5 toolchain
description: Install musl 1.2.5 from source and configure the linker for the requested target.
inputs:
  target:
    description: Cargo target triple that requires musl (e.g., x86_64-unknown-linux-musl).
    required: true
runs:
  using: composite
  steps:
    - name: Install musl 1.2.5
      shell: bash
      env:
        MUSL_VERSION: 1.2.5
        MUSL_PREFIX: /opt/musl-1.2.5
        DEBIAN_FRONTEND: noninteractive
      run: |
        set -euo pipefail
        sudo apt-get -y update -o Acquire::Retries=3
        sudo apt-get -y install --no-install-recommends build-essential curl pkg-config

        curl -sSfL --retry 3 --retry-delay 1 "https://musl.libc.org/releases/musl-${MUSL_VERSION}.tar.gz" -o /tmp/musl.tar.gz
        tar -xf /tmp/musl.tar.gz -C /tmp

        pushd "/tmp/musl-${MUSL_VERSION}"
        ./configure --prefix="${MUSL_PREFIX}"
        make -j"$(nproc)"
        sudo make install
        popd

        echo "${MUSL_PREFIX}/bin" >> "$GITHUB_PATH"
        musl_gcc="${MUSL_PREFIX}/bin/musl-gcc"
        "${musl_gcc}" --version

        case "${{ inputs.target }}" in
          x86_64-unknown-linux-musl)
            echo "CC_x86_64_unknown_linux_musl=${musl_gcc}" >> "$GITHUB_ENV"
            echo "CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_LINKER=${musl_gcc}" >> "$GITHUB_ENV"
            ;;
          aarch64-unknown-linux-musl)
            echo "CC_aarch64_unknown_linux_musl=${musl_gcc}" >> "$GITHUB_ENV"
            echo "CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_LINKER=${musl_gcc}" >> "$GITHUB_ENV"
            ;;
          *)
            echo "Unsupported musl target '${{ inputs.target }}'" >&2
            exit 1
            ;;
        esac