I find it difficult to see a standard where Rust is not ready for "serious work" but Haskell is.

I can install a working Haskell toolchain with my package manager instead of the farcical `curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh`.

If you're an automation-oriented kind of person like it's my job to be, setting up repeatable toolchians based around the above is a total crock of shit.

Rust/rustup is in every package manager like ever. As someone who is "automation-oriented" you sound like you don't have the faintest idea what you are talking about.

Which package manager do you use that doesn't have rustc and cargo packaged yet?

If you think this is one of your stronger arguments, I think my point has been made.

Getting this right should be table stakes.

Every non-Rustacean who has suddenly had Rust forced into their workflows asks for this to be solved, specifically, and the Rust community keeps digging its heels in.

Haskell has its warts but it's not 101-level shit like this.

"Getting this right" is a matter of opinion, and either way, rust can be installed a variety of ways. Your argument is literally nonsensical and demonstrates a seriously arrogance and lack of familiarity with what you're talking about.

What is your threat model that isn't solved by some combination of a rust-toolchain file and using your package manager (nix or whatever) to install rustup?

If you want to isolate your build machines from the internet entirely, you're either going to use a hermetic build system and have some equivalent of vendoring your compiler, or manage your own internal package repository in which case you can just add your own Rust + Cargo build to it.

If you're paranoid about building the Rust compiler from source, you can even put in the effort into bootstrapping your own lineage. But given that you're ok relying on your package manager for Haskell, it seems like this isn't a huge problem for you.

What did you think those warts were?

I use Rust for just about everything and I can definitely think of plenty of warts, but none of them make it "not quite ready for serious work" for my definitions of "serious work". I guess my point is that I'm curious what serious work this user is doing that Rust is unsuitable for - that kind of information is useful for language evolution, among other things.