In my WWX 2016 presentation on how we used Haxe with Unity I talked about that we integrated Haxe in right in our repository so there is no need to install Haxe on developers' machines and we can easily update Haxe version.

After that I received an email asking how to do it, so I'll describe what's needed in this short post. It's not really tied to Unity and is just about how to run local Haxe installation.

So what we basically did is put haxe executables (for Windows and macOS) and needed haxelibs (e.g. hxcs) into our project and wrote a simple build script that runs Haxe executable with required environment variables, here they are:

• HAXEPATH - path to the directory where Haxe executable is located. I'm not sure this is actually needed, but it was present in my system haxe installation. As far as I know it's only used in Windows for determining default haxelib repository path ($HAXEPATH/lib). There's also some code in Haxe's Neko generator that uses the same convention for loading .ndll files. I didn't look further and I just used the lib subdirectory for haxelibs as well.

• HAXELIB_PATH - path to the haxelib repository. This is where we put haxelibs needed for our project, such as hxcs, required to build for C#. As mentioned above we put it next to haxe executables named as lib.

• HAXE_STD_PATH - path to the Haxe standard library (the std folder, which we put in the same directory as Haxe executables). This one is important because if it's not present, Haxe will look for standard library in a set of hard-coded locations which will be invalid in our case of local haxe installation.

• NEKOPATH - path to the neko installation. I believe it's needed for loading standard .ndll files. We have it in separate folders for different platforms and set the env var dependeing on whether we're on Windows or macOS.

• DYLD_FALLBACK_LIBRARY_PATH - also path to the neko installation. This is only needed on macOS for loading dynamic libraries. I don't remember exactly, but I think this was needed for Haxe macros to work properly, since they load neko libraries for some functionality, like regexp.

Finally, we add HAXEPATH and NEKOPATH to the PATH env variable so neko and haxe can be called from further scripts without specifying the full path. Note that under macOS the separator between those should be : while on Windows it's ;.

So here's what our directory hierarchy looks like:

  * project
    * haxe/
      * lib/
        * hxcs/
        * hxnodejs/
        * etc...
      * neko-2.0.0-osx/
      * neko-2.0.0-win/
      * std/
      * haxe (osx executable)
      * haxelib (osx executable)
      * haxe.exe (win executable)
      * haxelib.exe (win executable)
      * zlib1.dll (needed this for windows because of how I build haxe)

Hope this helps, feel free to ask more in comments!