This is drive C: in the Rustbelt shell (/mnt/disk1): an ext2 file system.
Try: ls -l C:/   cat C:/hello-link   cp B:/notes/todo.txt C:/
Files made by build.rs: big.txt (indirect blocks), sparse.bin (a 66 MiB
file that is mostly holes), and the symlinks hello-link and docs/long-link.