Steps to reproduce

Install toolchains:

rustup toolchain install nightly-2018-11-25
rustup toolchain install nightly-2018-11-26

Build with nightly-2018-11-25:

$ cargo +nightly-2018-11-25 build --release
    Finished release [optimized] target(s) in 0.91s

Build with nightly-2018-11-26:

$ cargo +nightly-2018-11-26 build --release
    Finished release [optimized] target(s) in 8.24s