rand VS cargo-xtask

This may very well be a bit offtopic in the rust subreddit, but in case you need fast high quality non-crypto PRNG in Go, I've made one that I believe to be decent. It is unfortunate that math/rand is unlikely to significantly improve due to the backward compatibity and can't be recommended for anything non-trivial.

I got a bit stuck trying to find a set of good permutation functions for all required bit widths; I've created an issue to collect information in one place.

💡 Inspired by matklad/cargo-xtask and based on 🏃‍♂️ Write your Rust project scripts in task.rs from the Rust ecosystem.

Using a cargo-xtask task to generate them as a manual step (inlyne currently does this)

As someone else said just is good for that job, or you could implement an xtask helper for these things and setup a suitable development environment with that: https://github.com/matklad/cargo-xtask/

Well tools like cornucopia, prisma-rust-client, protoc-gen-tonic, they don't generate in build.rs, but instead provide either a cli to be called ahead of time, or provide a library that can be called by your own binary (which should generally follow the xtask pattern)

If I understand, this is a tool for when working on the project itself? Akin to a helper script? You could go the cargo install route as already pointed out but there is also the xtask convention.

For simple cli apps for internal use, such as cargo-xtasks, I prefer pico_args due to its fast compile times.

For developer-oriented stuff, there's tools like xshell and cargo-xtask. For operator tasks that need to run in a deployed environment, it's not usually a big lift to add CLI subcommands to your binary. It's certainly more boilerplate and inertia than doing stuff in a live REPL, though, and sometimes difficult to recommend for truly one-off situations.