Rust branch fails to build on the latest Nightly

[lovesegfault]

The rust branch must be build on a nightly toolchain, yet it fails to build on the latest nightly.

[lovesegfault]

Here's a build log, showing the errors.

These would suggest that some change has been made to the libarchive-rust library, but checking the repository this does not seem to be true. I even removed the [replace] hack with fetching the dependency straight through git, but the errors persist. I'm not entirely sure why those methods are missing, and where did they come from in the first place.

@vodik perhaps you can give some light to this weirdness? :)