Concurrent rustup toolchain add overwrite each others downloads

[kornelski]

Problem

Running multiple instances of rustup toolchain add X causes redundant downloads and installation errors.

This problem can happen when tests or CI tooling run concurrently tries to automatically install required versions of Rust.

 error: component download failed for cargo-aarch64-apple-darwin

Caused by:
    could not rename downloaded file from '…/.rustup/downloads/fc9eb10567ad9b477180d40669c4e6f8edc48f54083689f4a0b4a49db1815b37.partial' to '…/.rustup/downloads/fc9eb10567ad9b477180d40669c4e6f8edc48f54083689f4a0b4a49db1815b37'

Steps

rustup toolchain add 1.63 & rustup toolchain add 1.63 & rustup toolchain add 1.63

Possible Solution(s)

There should be some global locking mechanism, or downloads/installs should at least use randomized temporary file names.

Notes

No response

Rustup version

rustup 1.27.0 (c7b305727 2024-02-14)

Installed toolchains

not relevant

[kornelski]

Even when different versions are installed, they can fail due to apparently sharing some files?

error: failed to install component: 'rust-std-aarch64-apple-darwin', detected conflict: 'lib/rustlib/aarch64-apple-darwin/lib/libprofiler_builtins-2b6411659b64a644.rlib'

[ChrisDenton]

See the pinned issue: #988