With rustc 1.0.0-nightly (4be79d6ac 2015-01-23 16:08:14 +0000), there is the error: `error: unknown codegen option: ' no-trans'` This is because the option `--no-trans` was changed to `-Z no-trans` in https://github.com/rust-lang/rust/pull/19900