[INFO] fetching crate arc_ast 0.1.0...
[INFO] checking arc_ast-0.1.0 against beta for pr-78714
[INFO] extracting crate arc_ast 0.1.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate arc_ast 0.1.0 on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate arc_ast 0.1.0
[INFO] finished tweaking crates.io crate arc_ast 0.1.0
[INFO] tweaked toml for crates.io crate arc_ast 0.1.0 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] aca20c5a0b113c2d65dc2985f656c4bbe32ca94cc6affc0f81d97e008871fdbc
[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" "aca20c5a0b113c2d65dc2985f656c4bbe32ca94cc6affc0f81d97e008871fdbc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "aca20c5a0b113c2d65dc2985f656c4bbe32ca94cc6affc0f81d97e008871fdbc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aca20c5a0b113c2d65dc2985f656c4bbe32ca94cc6affc0f81d97e008871fdbc", kill_on_drop: false }`
[INFO] [stdout] aca20c5a0b113c2d65dc2985f656c4bbe32ca94cc6affc0f81d97e008871fdbc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=forbid" "-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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--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] c689d4e1560b54469bf9048916ffa4e81cd62db197d69f7685ddfc030b2d6250
[INFO] running `Command { std: "docker" "start" "-a" "c689d4e1560b54469bf9048916ffa4e81cd62db197d69f7685ddfc030b2d6250", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.117
[INFO] [stderr]    Compiling syn v1.0.48
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]     Checking num-integer v0.1.44
[INFO] [stderr]    Compiling serde_derive v1.0.117
[INFO] [stderr]     Checking num v0.2.1
[INFO] [stderr]     Checking arc_number v0.1.1
[INFO] [stderr]     Checking arc_ast v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `ops::IndexMut`
[INFO] [stdout]  --> src/utils/ast_impl.rs:4:34
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::{collections::VecDeque, ops::IndexMut};
[INFO] [stdout]   |                                  ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Error`
[INFO] [stdout]  --> src/utils/ast_traits.rs:4:33
[INFO] [stdout]   |
[INFO] [stdout] 4 |     fmt::{self, Debug, Display, Error, Formatter},
[INFO] [stdout]   |                                 ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::VecDeque`
[INFO] [stdout]  --> src/lib.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::collections::VecDeque;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `ops::IndexMut`
[INFO] [stdout]  --> src/utils/ast_impl.rs:4:34
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::{collections::VecDeque, ops::IndexMut};
[INFO] [stdout]   |                                  ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Error`
[INFO] [stdout]  --> src/utils/ast_traits.rs:4:33
[INFO] [stdout]   |
[INFO] [stdout] 4 |     fmt::{self, Debug, Display, Error, Formatter},
[INFO] [stdout]   |                                 ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::VecDeque`
[INFO] [stdout]  --> src/lib.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::collections::VecDeque;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `length` is assigned to, but never used
[INFO] [stdout]   --> src/utils/ast_traits.rs:71:21
[INFO] [stdout]    |
[INFO] [stdout] 71 |                 let mut length = 0;
[INFO] [stdout]    |                     ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout]    = note: consider using `_length` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `length` is assigned to, but never used
[INFO] [stdout]   --> src/utils/ast_traits.rs:71:21
[INFO] [stdout]    |
[INFO] [stdout] 71 |                 let mut length = 0;
[INFO] [stdout]    |                     ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout]    = note: consider using `_length` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 19.43s
[INFO] running `Command { std: "docker" "inspect" "c689d4e1560b54469bf9048916ffa4e81cd62db197d69f7685ddfc030b2d6250", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c689d4e1560b54469bf9048916ffa4e81cd62db197d69f7685ddfc030b2d6250", kill_on_drop: false }`
[INFO] [stdout] c689d4e1560b54469bf9048916ffa4e81cd62db197d69f7685ddfc030b2d6250