How to speed up IL2CPP builds? Distributed compilation possible?

Using Xcode, IL2CPP builds compile much more slowly than mono, and certain types of debugging require a “change, rebuild, change, rebuild” workflow. It’s a pain.

Is there any way these builds can be sped up? The ability to make a distributed build might help (distcc), since a coworker has a very fast computer. Object caching might also help (ccache), if the generated C++ code is the same each time.

In short, are there any tools or techniques I can use to increase a Unity game’s compilation in Xcode?

I’m not aware of anyone using distributed builds with Xcode, but it certainly should be possible, as there is nothing special about the C++ code generated bug IL2CPP.

Note that in the latest version of Unity, we’ve improved the ability for IL2CPP to generate “stable” C++ code. That is, a small change to the managed code should only cause a small change to the generated C++ code. So you should be able to use the incremental build capability in Xcode to shorten the “change, rebuild, change, rebuild” cycles.

Note that you need to us the “Append” option when building for iOS to allow this to work though. I’ll be happy to hear any feedback about incremental builds as well.