Blocking waiting for file lock on the registry index error in Rust

What helped for me was going to the task manager through CTRL+ALT+DELETE and selecting all the cargo.exe services and terminate them, and then reopen my IDE (Visual Code). Basically cargo the package manager was trying to launch multiple instances on the same project at once. Did this, and then just ran cargo clean and then cargo build without any problems. If you are in a Linux environment, try the following command in the terminal: sudo pkill rls cargo.