[INFO] crate oncemutex 0.1.1 is already in cache
[INFO] testing oncemutex-0.1.1 against beta-2020-07-24 for beta-1.46-1
[INFO] extracting crate oncemutex 0.1.1 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate oncemutex 0.1.1 on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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 /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-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@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a04a01e0844c9f8b405f9fc97fc1058bbc869a0e3a507eaa8969ffb36e5edc34
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "a04a01e0844c9f8b405f9fc97fc1058bbc869a0e3a507eaa8969ffb36e5edc34", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a04a01e0844c9f8b405f9fc97fc1058bbc869a0e3a507eaa8969ffb36e5edc34", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a04a01e0844c9f8b405f9fc97fc1058bbc869a0e3a507eaa8969ffb36e5edc34", kill_on_drop: false }`
[INFO] [stdout] a04a01e0844c9f8b405f9fc97fc1058bbc869a0e3a507eaa8969ffb36e5edc34
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-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@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b38ed19a4b9ad657829aae4403feb44882e3a65d2dfc64a7892801dc2acb7e59
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "b38ed19a4b9ad657829aae4403feb44882e3a65d2dfc64a7892801dc2acb7e59", kill_on_drop: false }`
[INFO] [stderr]    Compiling oncemutex v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]   --> src/lib.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         unsafe { self.data.into_inner() }
[INFO] [stdout]    |         ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/lib.rs:1:23
[INFO] [stdout]    |
[INFO] [stdout] 1  | #![deny(missing_docs, warnings)]
[INFO] [stdout]    |                       ^^^^^^^^
[INFO] [stdout]    = note: `#[warn(unused_unsafe)]` implied by `#[warn(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.22s
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "b38ed19a4b9ad657829aae4403feb44882e3a65d2dfc64a7892801dc2acb7e59", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b38ed19a4b9ad657829aae4403feb44882e3a65d2dfc64a7892801dc2acb7e59", kill_on_drop: false }`
[INFO] [stdout] b38ed19a4b9ad657829aae4403feb44882e3a65d2dfc64a7892801dc2acb7e59
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-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@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bfae9bd7e628cdd8b221e5bfbdb95a6491e6909015328f4cc31498f3219cc0f4
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "bfae9bd7e628cdd8b221e5bfbdb95a6491e6909015328f4cc31498f3219cc0f4", kill_on_drop: false }`
[INFO] [stderr]    Compiling oncemutex v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]   --> src/lib.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         unsafe { self.data.into_inner() }
[INFO] [stdout]    |         ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/lib.rs:1:23
[INFO] [stdout]    |
[INFO] [stdout] 1  | #![deny(missing_docs, warnings)]
[INFO] [stdout]    |                       ^^^^^^^^
[INFO] [stdout]    = note: `#[warn(unused_unsafe)]` implied by `#[warn(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:2:19
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![cfg_attr(test, feature(test))]
[INFO] [stdout]   |                   ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `oncemutex`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "bfae9bd7e628cdd8b221e5bfbdb95a6491e6909015328f4cc31498f3219cc0f4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bfae9bd7e628cdd8b221e5bfbdb95a6491e6909015328f4cc31498f3219cc0f4", kill_on_drop: false }`
[INFO] [stdout] bfae9bd7e628cdd8b221e5bfbdb95a6491e6909015328f4cc31498f3219cc0f4