Mac OS X

Disclaimer: Currently, the following steps are tested and confirmed to work on Linux only.

Use case

Exporting for Mac OS X is interesting if:

  • you do not have access to Apple hardware
  • you want to build from a CI, typically on a Docker image

If you have access to a real Mac, building natively is easier.

Why is this complex ?

Cross-compiling Rust programs for Mac OS X is as simple as:

rustup target add x86_64-apple-darwin
cargo build --target x86_64-apple-darwin

However to build gdnative-sys you need a Mac OS X C/C++ compiler, the Rust compiler is not enough. More precisely you need an SDK which usually comes with Xcode. For Mac users, this SDK is "just there" but when cross-compiling, it is typically missing, even if your compiler is able to produce Mac OS X compatible binaries.

The most common error is:

fatal error: 'TargetConditionals.h' file not found

Installing just this file is not enough, this error is usually a consequence of the whole SDK missing, so there is no chance you can get a build.

What you need to do is:

  • download the SDK
  • fix all paths and other details so that it ressembles a Mac OS X environment
  • then build with cargo build --target x86_64-apple-darwin

Hopefully, the first two steps, downloading the SDK and fixing details, are handled by a tool called osxcross which is just about setting up a working C/C++ compiler on Linux.


# make sure you have a proper C/C++ native compiler first, as a suggestion:
sudo apt-get install llvm-dev libclang-dev clang libxml2-dev libz-dev

# change the following path to match your setup
export MACOSX_CROSS_COMPILER=$HOME/macosx-cross-compiler

install -d $MACOSX_CROSS_COMPILER/osxcross
install -d $MACOSX_CROSS_COMPILER/cross-compiler
git clone && cd osxcross

# picked this version as they work well with godot-rust, feel free to change
git checkout 7c090bd8cd4ad28cf332f1d02267630d8f333c19

At this stage you need to download and package the SDK which can not be distributed with osxcross for legal reasons. Please ensure you have read and understood the Xcode license terms before continuing.

You should now have an SDK file, for example MacOSX10.10.sdk.tar.xz.

# move the file where osxcross expects it to be
mv MacOSX10.10.sdk.tar.xz $MACOSX_CROSS_COMPILER/osxcross/tarballs/
# build and install osxcross

At this stage, you should have, in $MACOSX_CROSS_COMPILER/cross-compiler, a working cross-compiler.

Now you need to tell Rust to use it when linking Mac OS X programs:

echo "[target.x86_64-apple-darwin]" >> $HOME/.cargo/config
find $MACOSX_CROSS_COMPILER -name x86_64-apple-darwin14-cc -printf 'linker = "%p"\n' >> $HOME/.cargo/config
echo >> $HOME/.cargo/config

After this, your $HOME/.cargo/config (not the cargo.toml file in your project, this is a different file) should contain:

linker = "/home/my-user-name/macosx-cross-compiler/cross-compiler/bin/x86_64-apple-darwin14-cc"

Then, we need to also tell the compiler to use the right compiler and headers. In our example, with SDK 10.10, the env vars we need to export are:


You probably do not want to export those permanently as they are very specific to building for Mac OS X so they are typically passed at each call to cargo, eg:

C_INCLUDE_PATH=$MACOSX_CROSS_COMPILER/cross-compiler/SDK/MacOSX10.10.sdk/usr/include CC=$MACOSX_CROSS_COMPILER/cross-compiler/bin/x86_64-apple-darwin14-cc cargo build --release --target x86_64-apple-darwin

As a consequence, you do not need to put $MACOSX_CROSS_COMPILER/cross-compiler/bin in your $PATH if you only plan to export godot-rust based programs, as the binary needs to be explicitly overloaded.


Once your .dylib file is built, a standard Godot export should work:

godot --export "Mac OSX" path/to/

Note that when exporting from a non Mac OS X platform, it is not possible to build a .dmg. Instead, a .zip is produced. Again, the tool required to build Mac OS X disk images is only available on Mac OS X. The .zip works fine though, it just contains folder, ready to use.

Double-check your .dylib file is there.