An unknown "kind" was specified for a link attribute. Erroneous code example:

```ignore (cannot-test-this-because-rustdoc-stops-compile-fail-before-codegen)
#[link(kind = "wonderful_unicorn")] extern {}
// error: unknown kind: `wonderful_unicorn`
```

Please specify a valid "kind" value, from one of the following:

* static
* dylib
* framework