[INFO] fetching crate marks 0.1.0...
[INFO] testing marks-0.1.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate marks 0.1.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate marks 0.1.0 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate marks 0.1.0
[INFO] finished tweaking crates.io crate marks 0.1.0
[INFO] tweaked toml for crates.io crate marks 0.1.0 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate crates.io crate marks 0.1.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5b5e9f3fcdf10c3009e06d1097d8c65f912fbc2ff6e4e6047022f23e17d36efc
[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" "5b5e9f3fcdf10c3009e06d1097d8c65f912fbc2ff6e4e6047022f23e17d36efc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5b5e9f3fcdf10c3009e06d1097d8c65f912fbc2ff6e4e6047022f23e17d36efc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5b5e9f3fcdf10c3009e06d1097d8c65f912fbc2ff6e4e6047022f23e17d36efc", kill_on_drop: false }`
[INFO] [stdout] 5b5e9f3fcdf10c3009e06d1097d8c65f912fbc2ff6e4e6047022f23e17d36efc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", 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] 2ab88535a6511a75b7aa431705fa235c618f3b4f30bba38a994efb2e145931a3
[INFO] running `Command { std: "docker" "start" "-a" "2ab88535a6511a75b7aa431705fa235c618f3b4f30bba38a994efb2e145931a3", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling syn v1.0.54
[INFO] [stderr]    Compiling paw-raw v1.0.0
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling dirs-sys v0.3.5
[INFO] [stderr]    Compiling fuzzy-matcher v0.3.7
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.1
[INFO] [stderr]    Compiling crossbeam-channel v0.5.0
[INFO] [stderr]    Compiling dirs v2.0.2
[INFO] [stderr]    Compiling clap v2.33.3
[INFO] [stderr]    Compiling term v0.6.1
[INFO] [stderr]    Compiling crossbeam-deque v0.8.0
[INFO] [stderr]    Compiling rayon-core v1.9.0
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling rayon v1.5.0
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling paw-attributes v1.0.2
[INFO] [stderr]    Compiling structopt-derive v0.4.14
[INFO] [stderr]    Compiling paw v1.0.0
[INFO] [stderr]    Compiling structopt v0.3.21
[INFO] [stderr]    Compiling marks v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(iterator_fold_self)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `rayon::prelude`
[INFO] [stdout]  --> src/marks.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use rayon::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning 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 `marks` due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "2ab88535a6511a75b7aa431705fa235c618f3b4f30bba38a994efb2e145931a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2ab88535a6511a75b7aa431705fa235c618f3b4f30bba38a994efb2e145931a3", kill_on_drop: false }`
[INFO] [stdout] 2ab88535a6511a75b7aa431705fa235c618f3b4f30bba38a994efb2e145931a3