So not only the post ended up with two (IMHO) bad recommendations (disabling debug info, building non-relocatable binaries with musl). But it also didn't mention other important factors like codegen-unitsand codegen-backend. Since you know, code generation is the other big contributor to the cycle time (the primary contributor even, in many cases). There is also other relevant options like lto and opt-level.

Let's assume that opt-level shouldn't be changed from defaults for no good reason.

With codegen-units, it's not the default that is the problem, but the fact that some projects set it to 1 (for performance optimization reasons), but without adding a separate profile for development release builds (let's call it release-dev).

Same goes for lto, where you can have it set to "full" in your optimized profile, and completely "off" in release-dev.

And finally, with codegen-backend, you can enjoy what is probably the biggest speed up in the cycle by using cranelift in your release-dev profile.

And of course you are not limited to just two release profiles. I usually use 3-4 myself. Profile inheritance makes this easy.

And finally, you can set/not set some of those selectively for your dependencies. For example, not using cranelift for dependencies can render the runtime performance delta negligible in some projects.

Using the parallel rustc front-end might become an interesting option too, but it's not ready yet.

[–] Deebster@infosec.pub 2 points 8 hours ago* (last edited 8 hours ago)

[target.x86_64-unknown-linux-gnu]
linker = "/usr/bin/clang-15"`
rustflags = ["-C", "link-arg=--ld-path=/usr/local/bin/mold"]

Can you put something like mold or env mold for better portability?

If not, I guess it's not so bad to edit and do git update-index --assume-unchanged .cargo/config.toml but it's a bit hacky since any further changes also get ignored.