[INFO] fetching crate lru2 0.1.0...
[INFO] testing lru2-0.1.0 against 1.60.0 for beta-1.61-1
[INFO] extracting crate lru2 0.1.0 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate lru2 0.1.0 on toolchain 1.60.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate lru2 0.1.0
[INFO] finished tweaking crates.io crate lru2 0.1.0
[INFO] tweaked toml for crates.io crate lru2 0.1.0 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "fetch" "--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" "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:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1a44f276a05a708d5c3178005bc7aa1c1c0fe535d26faa8634f01b18a01b81cb
[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" "1a44f276a05a708d5c3178005bc7aa1c1c0fe535d26faa8634f01b18a01b81cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1a44f276a05a708d5c3178005bc7aa1c1c0fe535d26faa8634f01b18a01b81cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a44f276a05a708d5c3178005bc7aa1c1c0fe535d26faa8634f01b18a01b81cb", kill_on_drop: false }`
[INFO] [stdout] 1a44f276a05a708d5c3178005bc7aa1c1c0fe535d26faa8634f01b18a01b81cb
[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" "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" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:eaef2f80f755933c374d2ae5edccceec0c1312ceb8a4e0b6404e8ab76561e1e5" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3a93ea2c1fde533527360958b4a22c49952af9344b93c9b1c8b486ab5765721b
[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" "3a93ea2c1fde533527360958b4a22c49952af9344b93c9b1c8b486ab5765721b", kill_on_drop: false }`
[INFO] [stderr]    Compiling lru2 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/cache/mod.rs:50:21
[INFO] [stdout]    |
[INFO] [stdout] 50 |                 let mut cache: &mut Register<C::LowerKey, C::Payload> = unsafe{ &mut **pcache };
[INFO] [stdout]    |                     ----^^^^^
[INFO] [stdout]    |                     |
[INFO] [stdout]    |                     help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/cache/mod.rs:57:13
[INFO] [stdout]    |
[INFO] [stdout] 57 |         let mut cache: &mut Register<C::LowerKey, C::Payload> = unsafe{ &mut **self.register.get(upper_key).unwrap() };
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(test)]
[INFO] [stdout]   |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lru2` due to 2 previous errors; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "3a93ea2c1fde533527360958b4a22c49952af9344b93c9b1c8b486ab5765721b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3a93ea2c1fde533527360958b4a22c49952af9344b93c9b1c8b486ab5765721b", kill_on_drop: false }`
[INFO] [stdout] 3a93ea2c1fde533527360958b4a22c49952af9344b93c9b1c8b486ab5765721b