Is there a simple way to use a local
rustc compiled from (modified) source locally with cargo (installed with Rustup)?
rustup toolchain link
Hi Amit! Check out this section of the rustc-dev-guide on creating a toolchain with your local build. https://rustc-dev-guide.rust-lang.org/building/how-to-build-and-run.html#creating-a-rustup-toolchain
Then you should be able to run it with e.g.,
cargo +stage1 build
50 minutes later, at almost the same second...