Beta testing rustup.rs

I guess you mean to run /c/Users/<user>/.multirust/toolchains/nightly-x86_64-pc-windows-gnu/bin/cargo.exe.

I tried it and it worked every time!

Then I realized the binaries under ~/.cargo/bin are some sort of wrappers or something which are actually calling the ones in ~/.multirust/toolchains/<toolchain>/bin. Maybe this indirection is causing all the problems.

Edit: fix typos