Build Instructions

You must be running a 64-bit x86 Linux distribution. Darling cannot be used on a 32-bit x86 system, not even to run 32-bit applications.

Dependencies

Clang is required to compile Darling; at least Clang 6 is required. You can force a specific version of Clang (if it is installed on your system) by editing Toolchain.cmake.

A minimum of 4 GB of RAM is also required for building. Using swap space may help reduce the memory usage, but is likely to slow the build down significantly.

Linux 5.0 or higher is required.

Debian 10/11

sudo apt install cmake clang-6.0 bison flex xz-utils libfuse-dev libudev-dev pkg-config \
libc6-dev-i386 libcap2-bin git git-lfs python2 libglu1-mesa-dev libcairo2-dev \
libgl1-mesa-dev libtiff5-dev libfreetype6-dev libxml2-dev libegl1-mesa-dev libfontconfig1-dev \
libbsd-dev libxrandr-dev libxcursor-dev libgif-dev libpulse-dev libavformat-dev libavcodec-dev \
libswresample-dev libdbus-1-dev libxkbfile-dev libssl-dev llvm-dev

Debian Testing

sudo apt install cmake clang-9 bison flex xz-utils libfuse-dev libudev-dev pkg-config \
libc6-dev-i386 libcap2-bin git git-lfs python2 libglu1-mesa-dev libcairo2-dev \
libgl1-mesa-dev libtiff5-dev libfreetype6-dev libxml2-dev libegl1-mesa-dev libfontconfig1-dev \
libbsd-dev libxrandr-dev libxcursor-dev libgif-dev libpulse-dev libavformat-dev libavcodec-dev \
libswresample-dev libdbus-1-dev libxkbfile-dev libssl-dev llvm-dev

Ubuntu 18.04/20.04:

sudo apt install cmake clang bison flex libfuse-dev libudev-dev pkg-config libc6-dev-i386 \
gcc-multilib libcairo2-dev libgl1-mesa-dev libglu1-mesa-dev libtiff5-dev \
libfreetype6-dev git git-lfs libelf-dev libxml2-dev libegl1-mesa-dev libfontconfig1-dev \
libbsd-dev libxrandr-dev libxcursor-dev libgif-dev libavutil-dev libpulse-dev \
libavformat-dev libavcodec-dev libswresample-dev libdbus-1-dev libxkbfile-dev \
libssl-dev python2

Arch Linux & Manjaro:

sudo pacman -S --needed make cmake clang flex bison icu fuse gcc-multilib \
lib32-gcc-libs pkg-config fontconfig cairo libtiff python2 mesa llvm libbsd libxkbfile \
libxcursor libxext libxkbcommon libxrandr ffmpeg git git-lfs

Fedora and CentOS

RPMFusion is required for FFmpeg.

sudo dnf install make cmake clang bison dbus-devel flex python2 glibc-devel.i686 fuse-devel \
systemd-devel elfutils-libelf-devel cairo-devel freetype-devel.{x86_64,i686} \
libjpeg-turbo-devel.{x86_64,i686} libtiff-devel.{x86_64,i686} fontconfig-devel.{x86_64,i686} \
libglvnd-devel.{x86_64,i686} mesa-libGL-devel.{x86_64,i686} mesa-libEGL-devel.{x86_64,i686} \
mesa-libGLU-devel.{x86_64,i686} libxml2-devel libbsd-devel git git-lfs libXcursor-devel \
libXrandr-devel giflib-devel ffmpeg-devel pulseaudio-libs-devel libxkbfile-devel \
openssl-devel llvm libcap-devel

OpenSUSE Tumbleweed

You will need to build Darling with only the 64bit components. See Build Options for instructions.

sudo zypper install make cmake-full clang10 bison flex python-base glibc fuse-devel \
libsystemd0 libelf1 cairo-devel libfreetype6 libjpeg-turbo libfontconfig1 libglvnd \
Mesa-libGL-devel Mesa-libEGL-devel libGLU1 libxml2-tools libbsd-devel git git-lfs \
libXcursor-devel giflib-devel ffmpeg-4 ffmpeg-4-libavcodec-devel \
ffmpeg-4-libavformat-devel libpulse-devel pulseaudio-utils libxkbfile-devel openssl \
llvm libcap-progs libtiff-devel libjpeg8-devel libXrandr-devel dbus-1-devel glu-devel \
ffmpeg-4-libswresample-devel

Alpine Linux

Make sure to enable the community repository. Alpine also doesn't support 32-bit builds, so make sure to disable that.

sudo apk add cmake clang bison flex xz fuse-dev pkgconfig libcap git git-lfs python2 \
python3 glu-dev cairo-dev mesa-dev tiff-dev freetype-dev libxml2-dev fontconfig-dev \
libbsd-dev libxrandr-dev libxcursor-dev giflib-dev pulseaudio-dev ffmpeg-dev dbus-dev \
libxkbfile-dev openssl-dev libexecinfo-dev make gcc g++ xdg-user-dirs

These are the minimum requirements for building and running Darling on Alpine. Of course, if you want to run GUI applications, you'll also need a desktop environment.

Fetch the Sources

Darling uses git-lfs. Set this up if needed with official instructions.

Darling makes extensive use of Git submodules, therefore you cannot use a plain git clone. Make a clone like this:

git clone --recursive https://github.com/darlinghq/darling.git

Attention: The source tree requires up to 5 GB of disk space!

Updating sources

If you have already cloned Darling and would like to get the latest changes, do this in the source root:

git lfs install
git pull
git submodule init
git submodule update

Build

The build system of Darling is CMake. Makefiles are generated by CMake by default.

Attention: The build may require up to 16 GB of disk space! The Darling installation itself then takes up to 1 GB.

Building and Installing

Now let's build Darling:

# Move into the cloned sources
cd darling

# Make a build directory
mkdir build && cd build

# Configure the build
cmake ..

# Build and install Darling
make
sudo make install

Build Options

Doing non-full (a.k.a. shallow) builds

You will notice that it takes a long time to build Darling. Darling contains the software layer equivalent to an entire operating system, which means it contains a large amount of code. You can optionally disable some large and less vital parts of the build in order to get faster builds.

To do this, use the -DFULL_BUILD=OFF option when configuring Darling through CMake.

You may encounter some things to be missing, such as JavaScriptCore. Before creating an issue about a certain library or framework missing from Darling, verify that you are doing a full build by not using this option or setting it to ON.

Disabling 32-bit Libraries

Darling normally builds both 32-bit and 64-bit versions of all libraries, to enable 32-bit programs to run under Darling. However, this means Darling also requires 32-bit version of certain native libraries. If you can't setup a multilib environment or you just want to build only the 64-bit components, use -DTARGET_i386=OFF during configuration to disable building the 32-bit components.

Parallel Builds

Another way to speed up the build is to run make with multiple jobs. For this, run make -j8 instead, where 8 is a number of current jobs to run of your choosing. In general, avoid running more jobs than twice the amount CPU cores of your machine.

"Unified" JavaScriptCore Builds

If you still want to build JavaScriptCore and have a bit of RAM to spare, JavaScriptCore also supports a build mode known as "unified builds". This build mode can cut JSC build times in half, at the expense of causing slightly higher RAM usage. This build mode can be enabled in Darling by adding -DJSC_UNIFIED_BUILD=ON when configuring the build.

Debug Builds

By default, CMake setups up a non-debug, non-release build. If you run LLDB and encounter messages indicating a lack of debug symbols, make sure you are doing a debug build. To do this, use -DCMAKE_BUILD_TYPE=Debug.

Unit tests

Darling has a limited number of unit tests. These are not currently built by default, but this can be enabled with '-DENABLE_TESTS=1'. These tests are then installed to /usr/libexec within your Darling container.

Additional, Non-standard Binaries

Darling tries to stick to a standard macOS installation as much as possible. However, if you would like to build and install some additional packages (such as GNU tar), you can add -DADDITIONAL_PACKAGES=ON.

Custom Installation Prefix

To install Darling in a custom directory use the CMAKE_INSTALL_PREFIX CMake option. However, a Darling installataion is NOT portable, because the installataion prefix is hardcoded into the darling executable. This is intentional. If you do move your Darling installation you will get this error message:

Cannot mount overlay: No such file or directory
Cannot open mnt namespace file: No such file or directory

If you wish to properly move your Darling installation, the only supported option is for you to uninstall your current Darling installation, and then rebuild Darling with a different installation prefix.

Known Issues

BackBox

If your distribution is Backbox and you run into build issues try the following commands:

sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-6.0 600
sudo update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-6.0 600

SELinux

On SELinux you may see the following error when starting Darling:

Cannot open mnt namespace file: No such file or directory

To work around this try this command: setsebool -P mmap_low_allowed 1.

Darling relies heavily on symbolic links. It is important to build Darling on a filesystem that supports this feature.

If you are still running into issues, despite downloading and building Darling on a filesystem that supports symbolic links, check your git configuration to make sure that you have not intentionally disabled it (ex: core.symlinks=false).

File System Support

Darling uses overlayfs for implementing prefixes on top of the macOS-like root filesystem. While overlayfs is not very picky about the lower (read-only) filesystem (where your /usr lives), it has stricter requirements for the upper filesystem (your home directory, unless you override the DPREFIX environment variable).

To quote the kernel documentation:

The lower filesystem can be any filesystem supported by Linux and does not need to be writable. The lower filesystem can even be another overlayfs. The upper filesystem will normally be writable and if it is it must support the creation of trusted.* extended attributes, and must provide valid d_type in readdir responses, so NFS is not suitable.

In addition to NFS not being supported, ZFS and eCryptfs encrypted storage are also known not to work.

If you try to use an unsupported file system, this error will be printed:

Cannot mount overlay: Invalid argument