[INFO] fetching crate cow_vec_item 0.5.1...
[INFO] testing cow_vec_item-0.5.1 against 1.75.0 for beta-1.76-1
[INFO] extracting crate cow_vec_item 0.5.1 into /workspace/builds/worker-2-tc1/source
[INFO] validating manifest of crates.io crate cow_vec_item 0.5.1 on toolchain 1.75.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate cow_vec_item 0.5.1
[INFO] finished tweaking crates.io crate cow_vec_item 0.5.1
[INFO] tweaked toml for crates.io crate cow_vec_item 0.5.1 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "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" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9e0c2c63b2431159608cd60c09ba220d38453b018ebbf34a3585867aef1f38d1
[INFO] running `Command { std: "docker" "start" "-a" "9e0c2c63b2431159608cd60c09ba220d38453b018ebbf34a3585867aef1f38d1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9e0c2c63b2431159608cd60c09ba220d38453b018ebbf34a3585867aef1f38d1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9e0c2c63b2431159608cd60c09ba220d38453b018ebbf34a3585867aef1f38d1", kill_on_drop: false }`
[INFO] [stdout] 9e0c2c63b2431159608cd60c09ba220d38453b018ebbf34a3585867aef1f38d1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 34a41a13c64cf2c474118ddc67b6ef459cb89c7cf50249492433465e4572dee7
[INFO] running `Command { std: "docker" "start" "-a" "34a41a13c64cf2c474118ddc67b6ef459cb89c7cf50249492433465e4572dee7", kill_on_drop: false }`
[INFO] [stderr]    Compiling cow_vec_item v0.5.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:511:13
[INFO] [stdout]     |
[INFO] [stdout] 511 |         let mut theref = unsafe { &mut *self.cowvec };
[INFO] [stdout]     |             ----^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:2:9
[INFO] [stdout]     |
[INFO] [stdout] 2   | #![deny(warnings)]
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     = note: `#[warn(unused_mut)]` implied by `#[warn(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.07s
[INFO] running `Command { std: "docker" "inspect" "34a41a13c64cf2c474118ddc67b6ef459cb89c7cf50249492433465e4572dee7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "34a41a13c64cf2c474118ddc67b6ef459cb89c7cf50249492433465e4572dee7", kill_on_drop: false }`
[INFO] [stdout] 34a41a13c64cf2c474118ddc67b6ef459cb89c7cf50249492433465e4572dee7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f1877a5664756dbba34cd13671025ddd30d78f28d101a9f2c43796bbca691fcd
[INFO] running `Command { std: "docker" "start" "-a" "f1877a5664756dbba34cd13671025ddd30d78f28d101a9f2c43796bbca691fcd", kill_on_drop: false }`
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:511:13
[INFO] [stdout]     |
[INFO] [stdout] 511 |         let mut theref = unsafe { &mut *self.cowvec };
[INFO] [stdout]     |             ----^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:2:9
[INFO] [stdout]     |
[INFO] [stdout] 2   | #![deny(warnings)]
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     = note: `#[warn(unused_mut)]` implied by `#[warn(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling cow_vec_item v0.5.1 (/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:3:27
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![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 `cow_vec_item` (lib test) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "f1877a5664756dbba34cd13671025ddd30d78f28d101a9f2c43796bbca691fcd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f1877a5664756dbba34cd13671025ddd30d78f28d101a9f2c43796bbca691fcd", kill_on_drop: false }`
[INFO] [stdout] f1877a5664756dbba34cd13671025ddd30d78f28d101a9f2c43796bbca691fcd
