Running cargo build gives errors like:

Process didn't exit successfully: `rustc - --crate-name - --crate-type dylib --crate-type bin --print=file-names` (status=101) --- stderr error: crate name cannot start with a hyphen: - error: aborting due to previous error

The nightly before that latest one is 2015-02-22 , which you can obtain/reobtain with the --date=2015-02-22 argument to rustup.sh , or via multirust default nightly-2015-02-22 .

This was possibly issue #1342, which is apparently fixed in master, but seemingly not in time to get into that nightly.