Cargo.toml

[package]
name = "test"
version = "0.0.1"
authors = [ "you@example.com" ]

[lib]
name = "test"
crate-type = ["staticlib"]

commands.txt

$ mkdir -p ./broken/link
$ mkdir test
$ ln -rs broken/link test/link
$ rmdir broken/link
$ cargo build
An unknown error occurred

To learn more, run the command again with --verbose.
$ cargo build -v
The system cannot find the path specified.
 (os error 3)