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.

It is recommended that you use at least Clang 3.8. You can force a specific version of Clang (if it is installed on your system) by editing Toolchain.cmake.

Linux 4.9 and higher is required.

sudo apt install cmake clang-4.0 bison flex xz-utils libfuse-dev libudev-dev pkg-config libc6-dev-i386 linux-headers-amd64 libcap2-bin git libcairo2-dev libgl1-mesa-dev libtiff5-dev libfreetype6-dev libxml2-dev libegl1-mesa-dev libfontconfig1-dev libbsd-dev libxrandr-dev libxcursor-dev libgif-dev

sudo apt install cmake clang-6.0 bison flex xz-utils libfuse-dev libudev-dev pkg-config libc6-dev-i386 linux-headers-amd64 libcap2-bin git libcairo2-dev libgl1-mesa-dev libtiff5-dev libfreetype6-dev libxml2-dev libegl1-mesa-dev libfontconfig1-dev libbsd-dev libxrandr-dev libxcursor-dev libgif-dev

sudo apt install cmake clang-7 bison flex xz-utils libfuse-dev libudev-dev pkg-config libc6-dev-i386 linux-headers-amd64 libcap2-bin git libcairo2-dev libgl1-mesa-dev libtiff5-dev libfreetype6-dev libxml2-dev libegl1-mesa-dev libfontconfig1-dev libbsd-dev libxrandr-dev libxcursor-dev libgif-dev

sudo apt install cmake clang bison flex libfuse-dev libudev-dev pkg-config libc6-dev-i386 linux-headers-generic gcc-multilib libcairo2-dev libgl1-mesa-dev libtiff5-dev libfreetype6-dev git libelf-dev libxml2-dev libegl1-mesa-dev libfontconfig1-dev libbsd-dev libxrandr-dev libxcursor-dev libgif-dev

sudo pacman -S --needed make cmake clang flex bison icu fuse linux-headers gcc-multilib lib32-gcc-libs pkg-config fontconfig cairo libtiff python2 mesa llvm

Make sure you install the headers package that matches your kernel version. The kernel version can be checked with uname -r.

$ uname -r
5.4.6-2-MANJARO

Then you should have linux54-headers installed. You will typically be prompted but may have to install this manually.

sudo dnf install make cmake clang bison flex python2 glibc-devel.i686 fuse-devel systemd-devel kernel-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} libxml2-devel libbsd-devel git libXcursor-devel giflib-devel

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

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

git pull
git submodule init
git submodule update

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

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

Darling also requires a kernel module named darling-mach:

make lkm
sudo make lkm_install

If module installation produces warnings such as SSL error:02001002:system library:fopen:No such file or directory: bss_file.c:175, then these can be usually ignored, unless you configured your system to enforce secure boot.

The kernel module is an experimental piece of code; it's likely to have many bugs and vulnerabilities. Be prepared for kernel hangups and crashes, and run Darling on a virtual machine if possible.

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 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.

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.

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 the -DCMAKE_BUILD_TYPE=Debug.

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-4.0 400
sudo update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-4.0 400

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.

If Secure Boot is enabled you may see:

modprobe: ERROR: could not insert 'darling_mach': Operation not permitted
Failed to load the kernel module

Use the following commands to generate a key and self-sign the kernel module:

# Generate Key
openssl req -new -x509 -newkey rsa:2048 -keyout MOK.priv -outform DER -out MOK.der -nodes -days 36500 -subj "/CN=Darling LKM/"
# Enroll Key
sudo mokutil --import MOK.der
# Sign Module
sudo kmodsign sha512 MOK.priv MOK.der /lib/modules/$(uname -r)/extra/darling-mach.ko
# Reboot System and Enroll Key

This error can occur for a number of reasons. The most common is that your currently running kernel is no longer installed, which occurs after an upgrade. Before trying other steps reboot your system in order to test against this.

Another cause is that the kernel headers may not be installed. Distributions such as Ubuntu will install the correct headers automatically, but Arch/Manjaro may require you to install the appropriate headers manually. See the “Arch Linux & Manjaro” section earlier on this page for instructions on how to install the appropriate Linux headers.

make -C /lib/modules/5.4.2-1-MANJARO/build M=/home/xeab/Downloads/darling/src/lkm modules
make[5]: Entering directory '/usr/lib/modules/5.4.2-1-MANJARO/build'
make[5]: *** No rule to make target 'modules'.  Stop.

Uninstall