Hello Brett

Unfortunately I can't predict whether a particular version will work or not. What I'd rather do, with the understanding of the problem I have so far, is to try to reduce the number of source files the il2cpp compiler has to compile. Perhaps by simplifying the code and/or merging some scripts. A good process would be : arbitrarily halve your codebase where it's most convenient, build. If it builds successfully, put back half of the half you removed. If it works, put back half of the remaining half. Etc. until it no longer works. At which point you get an idea of the "volume" of scripts where the problem starts to occur. It is even possible that a particular script (for example one brought in by a plugin/asset) produces a lot of source files to compile and triggers the case alone.

As the problem seemingly also occurs on macOS, and in all cases in the il2cpp building step which is driven by Unity's il2cpp compiler driver but is a sort of black box for the build system, I don't think I can do anything about it unfortunately, except for providing advice on how to avoid it, hopefully relevant.