[INFO] crate oncemutex 0.1.1 is already in cache
[INFO] testing oncemutex-0.1.1 against 1.45.2 for beta-1.46-1
[INFO] extracting crate oncemutex 0.1.1 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate oncemutex 0.1.1 on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "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-13/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "+1.45.2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 23e0d332bb3eadad474449d01f6c20b9307f47c95423f0c2d45d8c74421fd581
[INFO] running `Command { std: "docker" "start" "-a" "23e0d332bb3eadad474449d01f6c20b9307f47c95423f0c2d45d8c74421fd581", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "23e0d332bb3eadad474449d01f6c20b9307f47c95423f0c2d45d8c74421fd581", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "23e0d332bb3eadad474449d01f6c20b9307f47c95423f0c2d45d8c74421fd581", kill_on_drop: false }`
[INFO] [stdout] 23e0d332bb3eadad474449d01f6c20b9307f47c95423f0c2d45d8c74421fd581
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "+1.45.2" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c3e679b50c0f39d670aeeddfdb3322c655996b358a092b3a94db01628c95a749
[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" "c3e679b50c0f39d670aeeddfdb3322c655996b358a092b3a94db01628c95a749", 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" "c3e679b50c0f39d670aeeddfdb3322c655996b358a092b3a94db01628c95a749", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c3e679b50c0f39d670aeeddfdb3322c655996b358a092b3a94db01628c95a749", kill_on_drop: false }`
[INFO] [stdout] c3e679b50c0f39d670aeeddfdb3322c655996b358a092b3a94db01628c95a749
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "+1.45.2" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a43129a56f4516237cc63fbb314f6376f71fc642f7ebb55e3e8e80381b53189a
[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" "a43129a56f4516237cc63fbb314f6376f71fc642f7ebb55e3e8e80381b53189a", kill_on_drop: false }`
[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]    Compiling oncemutex v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable 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" "a43129a56f4516237cc63fbb314f6376f71fc642f7ebb55e3e8e80381b53189a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a43129a56f4516237cc63fbb314f6376f71fc642f7ebb55e3e8e80381b53189a", kill_on_drop: false }`
[INFO] [stdout] a43129a56f4516237cc63fbb314f6376f71fc642f7ebb55e3e8e80381b53189a