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Install the toolchain

Building a game library compiles Scala to Scala Native, then through LLVM/Clang to a native dynamic library. You need the JVM toolchain to run the build and a native toolchain to link the result.

Dependency Version Purpose
JDK 17 (Temurin recommended) Runs sbt and the Scala compiler.
sbt any launcher Build tool. Each project pins its own sbt version.
LLVM / Clang 16 or newer Scala Native compiles through Clang.
C/C++ build tools see tabs below System toolchain Scala Native links against.
Boehm GC (libgc + gc.h) any recent The library links the Boehm garbage collector (-lgc).
Godot 4.6.x, standard build Loads the built library. The .NET build is not needed.

Install Clang, LLD, and Boehm GC from your package manager.

sudo apt install clang lld libgc-dev

On Fedora use clang lld gc-devel. On Arch use clang lld gc.

Install JDK 17 and sbt via SDKMAN! or your distribution, and download Godot 4.6 from godotengine.org.

xcode-select --install

brew install llvm bdw-gc sbt openjdk@17

If Clang cannot find gc.h, point it at Homebrew's prefix:

export C_INCLUDE_PATH="$(brew --prefix bdw-gc)/include"
export LIBRARY_PATH="$(brew --prefix bdw-gc)/lib"

Run this in PowerShell to install everything except Godot and Boehm GC:

irm https://raw.githubusercontent.com/optical002/godot-scala-native/main/install-toolchain.ps1 | iex

The script detects what is already installed and uses winget, falling back to Scoop. It installs JDK 17, sbt, LLVM/Clang, the Visual Studio 2022 "Desktop development with C++" build tools, and Git. Re-running it is safe. The Visual Studio step may prompt for admin rights.

Boehm GC must be installed manually

The script currently fails at the Boehm GC step. Install bdwgc yourself, for example with vcpkg:

vcpkg install bdwgc:x64-windows

Then set C_INCLUDE_PATH to the folder containing gc.h and LIBRARY_PATH to the folder containing the library, so Clang can find them. Your first sbt godotBuild is where the .dll build is confirmed.

Non-standard install locations

The build does not hard-code any install prefix. Boehm GC must be on the standard search paths of Clang and the linker. If it lives elsewhere (for example a Nix store path), export these before building:

  • C_INCLUDE_PATH: the directory holding gc.h
  • LIBRARY_PATH: the directory holding libgc.*

See the Scala Native environment setup guide for the canonical per-OS instructions.

Check your setup

java -version

clang --version

godot --version

Next: Create a project.