Download the macOS SDK from Apple's Software Update servers, process it, and package it for cross-compiling macOS applications from Linux using Clang and LLD.

The macOS SDK is downloaded directly from Apple's public Software Update catalog (the same mechanism macOS uses for Command Line Tools updates). No Apple account is required.

The SDK includes:

• C/C++ headers (usr/include/)
• Library stubs as .tbd files (usr/lib/)
• macOS frameworks (System/Library/Frameworks/)

Supported target architectures: aarch64 (Apple Silicon) and x86_64 (Intel).

Generate, build, and install the RPMs:

./gen rpm --cache-dir .cache --install

Cross-compile with the installed helper scripts:

macos-aarch64-meson builddir
ninja -C builddir

macos-aarch64-cmake -B builddir
cmake --build builddir

macos-aarch64-config && macos-aarch64-make  # autotools (configure/make)

For projects that vendor the SDK instead of installing it system-wide:

./gen meson --cache-dir .cache --output-dir macos-cross

Link it into your project:

ln -s /path/to/macos-cross subprojects/macos-cross
meson setup builddir --cross-file hello-macos/aarch64-apple-darwin.txt
ninja -C builddir

In your meson.build:

macos_cross_dep = dependency('macos-cross')
executable('app', 'main.c', dependencies: macos_cross_dep)

The SDK subpackage (macos-cross-sdk) installs the SDK to /usr/share/macos-cross/sdk/.

Each arch subpackage (macos-cross-aarch64, macos-cross-x86_64) installs:

x86_64 equivalents use the x86_64-apple-darwin triple and a macos-x86_64- prefix.

The RPM pulls in clang, lld, and pkgconf-pkg-config as dependencies.

The macOS SDK only provides system frameworks and libraries. For third-party libraries (e.g., glib, openssl, libpng), use macos-brew to download pre-built Homebrew bottles directly into your cross-compilation sysroot:

macos-brew --arch aarch64 install glib

macos-brew fetches bottles from Homebrew's public API (no macOS or Homebrew installation required), verifies checksums, resolves dependencies automatically, and links everything into the sysroot so headers and libraries are found by the cross-compiler toolchain.

Common commands:

macos-brew search libpng              # Search available formulae
macos-brew info glib                  # Show formula details and dependencies
macos-brew install openssl glib       # Install formulae (with dependencies)
macos-brew upgrade                    # Upgrade all installed formulae
macos-brew list                       # List installed formulae
macos-brew uninstall glib             # Remove a formula

Options and environment variables:

The macos-brew script is included in the macos-cross-sdk RPM package.

If you already have a macOS SDK (e.g., from Xcode on a Mac):

./gen rpm --sdk-path /path/to/MacOSX15.5.sdk --cache-dir .cache

• Python 3 (for ./gen)
• cpio (for extracting Apple .pkg files)
• defusedxml (pip install defusedxml or dnf install python3-defusedxml)

For building:

• Clang + LLD (dnf install clang lld)
• Meson + Ninja (dnf install meson ninja-build)

The RPM packages pull in clang and lld automatically.

Common options (both ./gen rpm and ./gen meson):

--clt-version VERSION   Command Line Tools version (e.g. 16.4;
                        determines the macOS SDK version; default: latest)
--sdk-path PATH         Use a local SDK directory (skip download)
--cache-dir DIR         Cache for downloads (default: temp)
--output-dir DIR        Directory for generated files (default: .)
--list-versions         List available CLT versions and exit
--inspect               Show SDK contents without generating output

RPM-only options:

--install               Build and install RPMs after generation
--no-install            Skip RPM build/install (just generate spec + tarball)

When neither --install nor --no-install is given, the tool prompts interactively.

The generator scripts are in the public domain (no license restrictions). The downloaded macOS SDK is proprietary — see the generated LICENSE.txt. Do not upload the SDK output to public repositories.