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