Rustup toolchains

cargo-bisect-rustc takes advantage of rustup toolchains for installation and selecting the correct rustc to run. It will essentially run cargo +bisector-nightly-2023-03-18-x86_64-unknown-linux-gnu build using rustup toolchain override shorthand to run the toolchains that it downloads. This sets the RUSTUP_TOOLCHAIN environment variable to the toolchain name, which ensures that any call to rustc will use the correct toolchain.

By default, cargo-bisect-rustc will delete toolchains immediately after using them. You can use the --preserve option to keep the toolchains so that you can use them manually. See the Preserving toolchains example for more details.

When using the --script option, the script should just invoke cargo or rustc normally, and rely on the RUSTUP_TOOLCHAIN environment variable to pick the correct toolchain.