> I think the appropriate solution to this would be some form of arena allocator instead of changing the system allocator. But that gets even more complicated with lifetimes and stuff.

If you're doing arena allocation in a compiler you might as well just leak all your allocations (which you could get with bumpalo with a 'static lifetime); then you won't have to deal with lifetimes at all.

> Yeah, I could have tried restructuring my code to try to avoid compiler issues.

Well, my point is that it would be good for readability to restructure your code in that way even in Go. 500-line functions are hard to read.

> But this would have been even more time spent working around issues with Rust. Go was better than Rust by pretty much every metric that mattered for me, so I went with Go instead.

I find the opposite to be true, especially for compilers. It's hard for me to go back to a language without pattern matching and enums (much less generics, iterators, a package ecosystem, etc.). The gain of productivity from GC and compile times is not worth Go's loss in productivity in other areas for me. But reasonable people can disagree here.