[INFO] fetching crate clobber 0.2.1...
[INFO] testing clobber-0.2.1 against beta-2019-09-28 for beta-1.39-1
[INFO] extracting crate clobber 0.2.1 into work/builds/worker-4/source
[INFO] validating manifest of crates.io crate clobber 0.2.1 on toolchain beta-2019-09-28
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate clobber 0.2.1
[INFO] finished tweaking crates.io crate clobber 0.2.1
[INFO] tweaked toml for crates.io crate clobber 0.2.1 written to work/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate clobber 0.2.1 already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2019-09-28" "build" "--frozen"`
[INFO] [stdout] 8ef565b41467f255d30360855244d556ee08acb9877440ac09c300dc27723050
[INFO] running `"docker" "start" "-a" "8ef565b41467f255d30360855244d556ee08acb9877440ac09c300dc27723050"`
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling spin_sleep v0.3.7
[INFO] [stderr]    Compiling crossbeam-channel v0.3.9
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling getrandom v0.1.8
[INFO] [stderr]    Compiling fern v0.5.8
[INFO] [stderr]    Compiling nix v0.14.1
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling mio-uds v0.6.7
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling rand_core v0.5.0
[INFO] [stderr]    Compiling chrono v0.4.7
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling rand_chacha v0.2.1
[INFO] [stderr]    Compiling crossbeam v0.7.2
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling rand v0.7.0
[INFO] [stderr]    Compiling ctrlc v3.1.3
[INFO] [stderr]    Compiling futures-executor-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling futures-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling juliex v0.3.0-alpha.8
[INFO] [stderr]    Compiling futures-timer v0.3.0
[INFO] [stderr]    Compiling romio v0.3.0-alpha.9
[INFO] [stderr]    Compiling clobber v0.2.1 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]   --> src/lib.rs:26:1
[INFO] [stderr]    |
[INFO] [stderr] 26 | #![feature(async_await)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `clobber`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "8ef565b41467f255d30360855244d556ee08acb9877440ac09c300dc27723050"`
[INFO] running `"docker" "rm" "-f" "8ef565b41467f255d30360855244d556ee08acb9877440ac09c300dc27723050"`
[INFO] [stdout] 8ef565b41467f255d30360855244d556ee08acb9877440ac09c300dc27723050