Run miri without having to cargo install xargo

[ambroisie]

Hello, first of all thank you for working on this overlay.

I would like to know if there are plans to be able to use clippy without having to cargo install xargo.

I am not very familiar with miri so I'm not sure exactly how much it relies on having access to xargo or not. From what I can gather, it seems like it needs to be provided with a std compiled for miri. Could this crate be provided as an extra component in the overlay?

Otherwise, could adding the miri component also add xargo so that it doesn't try to imperatively install it on my computer?

[oxalica]

clippy works out-of-box. I'd assume you are referring to miri and cargo-miri.

I tried to package miri-sysroot before, in order to avoid xargo and cargo miri setup. But the key issue is that rust-src just contains a Cargo.toml for 3rd-party dependencies of std but not any vendored source. So it requires downloading these crates before building sysroot for MIRI.
Due to the network sandbox of Nix, we cannot easily package it without knowing hashes of vendored dep sources at eval-time.

BTW: Currently, to use MIRI, you first need to add extensions miri-preview and rust-src (eg. rust-bin.nightly."2022-07-30".default.override { extensions = [ "miri-preview" "rust-src" ]; }), run cargo miri setup which builds std with MIRI, then you should be able to use cargo miri on your projects.

[ambroisie]

clippy works out-of-box. I'd assume you are referring to miri and cargo-miri.

Oops indeed, I edited the issue to fix that.

BTW: Currently, to use MIRI, you first need to add extensions miri-preview and rust-src (eg. rust-bin.nightly."2022-07-30".default.override { extensions = [ "miri-preview" "rust-src" ]; }), run cargo miri setup which builds std with MIRI, then you should be able to use cargo miri on your projects.

Alright, I will do that in as long as we can't take care of it declaratively.

Thanks for the quick answer.