[INFO] crate oncemutex 0.1.1 is already in cache
[INFO] testing oncemutex-0.1.1 against beta-2019-09-28 for beta-1.39-1
[INFO] extracting crate oncemutex 0.1.1 into work/builds/worker-9/source
[INFO] validating manifest of crates.io crate oncemutex 0.1.1 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 oncemutex 0.1.1
[INFO] finished tweaking crates.io crate oncemutex 0.1.1
[INFO] tweaked toml for crates.io crate oncemutex 0.1.1 written to work/builds/worker-9/source/Cargo.toml
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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-9/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-9/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] 015eefee68b9c293e20e59dec536aebf0812891145277432d69d32813ad73410
[INFO] running `"docker" "start" "-a" "015eefee68b9c293e20e59dec536aebf0812891145277432d69d32813ad73410"`
[INFO] [stderr]    Compiling oncemutex v0.1.1 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unnecessary `unsafe` block
[INFO] [stderr]   --> src/lib.rs:86:9
[INFO] [stderr]    |
[INFO] [stderr] 86 |         unsafe { self.data.into_inner() }
[INFO] [stderr]    |         ^^^^^^ unnecessary `unsafe` block
[INFO] [stderr]    |
[INFO] [stderr] note: lint level defined here
[INFO] [stderr]   --> src/lib.rs:1:23
[INFO] [stderr]    |
[INFO] [stderr] 1  | #![deny(missing_docs, warnings)]
[INFO] [stderr]    |                       ^^^^^^^^
[INFO] [stderr]    = note: `#[warn(unused_unsafe)]` implied by `#[warn(warnings)]`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.23s
[INFO] running `"docker" "inspect" "015eefee68b9c293e20e59dec536aebf0812891145277432d69d32813ad73410"`
[INFO] running `"docker" "rm" "-f" "015eefee68b9c293e20e59dec536aebf0812891145277432d69d32813ad73410"`
[INFO] [stdout] 015eefee68b9c293e20e59dec536aebf0812891145277432d69d32813ad73410
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-9/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" "test" "--frozen" "--no-run"`
[INFO] [stdout] 377d6429e6ece25e8f93530f2c1bced7b9d149a8569c6fbe7b1955ada91ee75b
[INFO] running `"docker" "start" "-a" "377d6429e6ece25e8f93530f2c1bced7b9d149a8569c6fbe7b1955ada91ee75b"`
[INFO] [stderr]    Compiling oncemutex v0.1.1 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:2:19
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![cfg_attr(test, feature(test))]
[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 `oncemutex`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "377d6429e6ece25e8f93530f2c1bced7b9d149a8569c6fbe7b1955ada91ee75b"`
[INFO] running `"docker" "rm" "-f" "377d6429e6ece25e8f93530f2c1bced7b9d149a8569c6fbe7b1955ada91ee75b"`
[INFO] [stdout] 377d6429e6ece25e8f93530f2c1bced7b9d149a8569c6fbe7b1955ada91ee75b