Thanks for that very helpful tip! According to the output of that, no unnecessary recompilation is taking place. I actually figured out the issue! It turns out

Thanks for that very helpful tip! According to the output of that, no unnecessary recompilation is taking place. I actually figured out the issue! It turns out, I had unquestioningly transplanted the following from the blog post in discussion, and that is the cause of all my issues: [profile.dev] opt-level = 1 [profile.dev.package."*"] opt-level = 3 Removing that seems to give me an order (or two) of magnitude reduction in compile times. (Worth noting: it was passing RUSTFLAGS=-Ztime-passes that made me look here because, apparently, `llvm_passes` was taking the majority of the time).