I suspect dtolnay is trading a bit of his outsized influence on the community [1] to light a fire, and I think it's working.
Even a precompiled, sandboxed WASM binary is already too opaque. Sure, it cannot directly do bad things to the build machine (because it's sandboxed), but it still could inject malicious code into the final output of the compiler. And since it's a binary, it cannot be easily audited (through things like cargo-vet), unless it can be re-created from its source code through a reproducible build step.
And if it can be re-created through a reproducible build step, then it's not much more than a cache. Which points to the true issue being deficient caching of some intermediate build steps; distributing precompiled binaries should not be actually needed.
There is a reason why Rust doesn't yet have these sandboxed, pre-built macros and why the community needed a kick to get working on it. It's not easy, but it's entirely possible to reach the bar of auditability.
You realize that the first step people do when developing Rust is use a pre-compiled rustup to get a pre-compiled Rust binary toolchain, right?
Not necessarily, they could use their distribution's package manager to obtain the Rust compiler (which is what I do). Or they could use an older Rust compiler to build rustc and cargo from source (which is what I did back when Rust was newer). Yes, you cannot avoid having a pre-built compiler somewhere in the chain, but we should be working to minimize the number of these hard-to-audit dependencies, not increase them.
Mixing binaries with source code means the whole package is not FOSS anymore.
It is illogical to ship binaries for only part of a crate. Shipping binaries for the whole crates is much simpler and gives a much larger speed-up.
But ship the binaries separately from the source code.
This is completely untrue and a bad-faith argument. The source is right there for the binary. It's still FOSS.
You are right that my assumption in this unusual arrangement is that the binary does not necessarily correspond to (the same version of) the source code.
I would challenge you to find more than a half dozen crate authors with more downloads:
https://crates.io/users/dtolnay?sort=downloads
These are not `leftpad`-level crates. This is fundamental tech in the Rust ecosystem, especially in proc macro work.
I'd turn this around. If somebody as trusted as him, pulls such a stunt, how are we supposed to trust anybody?
> These are not `leftpad`-level crates.
They are like leftpad, because they're very popular (indirect) dependencies outside the control of the rust organization.
Calling his contributions leftpad is pretty rude, considering the massive difference between complexity and importance of the two
I've only had a handful of interactions with him and he's been a stand-up guy. I'll value the human over the outrage here.
Trust is easy to destroy and hard to build. This is trust destroying behavior. There may be some positives that result from this but his reputation may not recover and his motivation for this behavior may not get implemented, it's more likely that cargo just gets updated to block this behavior (good for all of us, but not the intended outcome).