[INFO] cloning repository https://github.com/Lakret/backtrack_rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Lakret/backtrack_rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLakret%2Fbacktrack_rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLakret%2Fbacktrack_rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 21a7dfdaf0c1a79561b1e3182f90e30563868603
[INFO] checking Lakret/backtrack_rs against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLakret%2Fbacktrack_rs" "/workspace/builds/worker-11/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Lakret/backtrack_rs 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 git repo https://github.com/Lakret/backtrack_rs
[INFO] finished tweaking git repo https://github.com/Lakret/backtrack_rs
[INFO] tweaked toml for git repo https://github.com/Lakret/backtrack_rs written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/Lakret/backtrack_rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] 20e0f8db3740c8f8a42ac35e9da44bcbf2f5ef98938015e04cc94e1ef33ff7f2
[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" "20e0f8db3740c8f8a42ac35e9da44bcbf2f5ef98938015e04cc94e1ef33ff7f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "20e0f8db3740c8f8a42ac35e9da44bcbf2f5ef98938015e04cc94e1ef33ff7f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "20e0f8db3740c8f8a42ac35e9da44bcbf2f5ef98938015e04cc94e1ef33ff7f2", kill_on_drop: false }`
[INFO] [stdout] 20e0f8db3740c8f8a42ac35e9da44bcbf2f5ef98938015e04cc94e1ef33ff7f2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] [stdout] 0066ad25d33b26b3a8a2e1bf925c98993a69eaa38e0d4881b6d3e10b18d63bc6
[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" "0066ad25d33b26b3a8a2e1bf925c98993a69eaa38e0d4881b6d3e10b18d63bc6", kill_on_drop: false }`
[INFO] [stderr]     Checking oorandom v11.1.1
[INFO] [stderr]     Checking serde_json v1.0.53
[INFO] [stderr]     Checking bstr v0.2.13
[INFO] [stderr]    Compiling serde_derive v1.0.110
[INFO] [stderr]     Checking plotters v0.2.14
[INFO] [stderr]     Checking rayon-core v1.7.0
[INFO] [stderr]     Checking crossbeam v0.7.3
[INFO] [stderr]     Checking backtrack_rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::thread::JoinHandle`
[INFO] [stdout]    --> src/lib.rs:210:5
[INFO] [stdout]     |
[INFO] [stdout] 210 | use std::thread::JoinHandle;
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iteration`
[INFO] [stdout]    --> src/lib.rs:284:3
[INFO] [stdout]     |
[INFO] [stdout] 284 |   iteration: u32,
[INFO] [stdout]     |   ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_iteration`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reduced_domain`
[INFO] [stdout]   --> src/ac3.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let reduced_domain = csp
[INFO] [stdout]    |             ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reduced_domain`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/ac3.rs:33:8
[INFO] [stdout]    |
[INFO] [stdout] 33 |       [x, y] => {}
[INFO] [stdout]    |        ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/ac3.rs:33:11
[INFO] [stdout]    |
[INFO] [stdout] 33 |       [x, y] => {}
[INFO] [stdout]    |           ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ac3.rs:15:7
[INFO] [stdout]    |
[INFO] [stdout] 15 |   let mut constraint_refs = csp.constraints.iter().collect::<Vec<_>>();
[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: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking rayon v1.3.0
[INFO] [stdout] warning: unused import: `lazy_static::lazy_static`
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use lazy_static::lazy_static;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking tinytemplate v1.0.4
[INFO] [stderr]     Checking csv v1.1.3
[INFO] [stderr]     Checking criterion v0.3.2
[INFO] [stdout] warning: unused import: `lazy_static::lazy_static`
[INFO] [stdout]  --> src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use lazy_static::lazy_static;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread::JoinHandle`
[INFO] [stdout]    --> src/lib.rs:210:5
[INFO] [stdout]     |
[INFO] [stdout] 210 | use std::thread::JoinHandle;
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iteration`
[INFO] [stdout]    --> src/lib.rs:284:3
[INFO] [stdout]     |
[INFO] [stdout] 284 |   iteration: u32,
[INFO] [stdout]     |   ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_iteration`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reduced_domain`
[INFO] [stdout]   --> src/ac3.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let reduced_domain = csp
[INFO] [stdout]    |             ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reduced_domain`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/ac3.rs:33:8
[INFO] [stdout]    |
[INFO] [stdout] 33 |       [x, y] => {}
[INFO] [stdout]    |        ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/ac3.rs:33:11
[INFO] [stdout]    |
[INFO] [stdout] 33 |       [x, y] => {}
[INFO] [stdout]    |           ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ac3.rs:15:7
[INFO] [stdout]    |
[INFO] [stdout] 15 |   let mut constraint_refs = csp.constraints.iter().collect::<Vec<_>>();
[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: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `black_box`
[INFO] [stdout]  --> benches/backtracking_bench.rs:1:17
[INFO] [stdout]   |
[INFO] [stdout] 1 | use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion};
[INFO] [stdout]   |                 ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 24.07s
[INFO] running `Command { std: "docker" "inspect" "0066ad25d33b26b3a8a2e1bf925c98993a69eaa38e0d4881b6d3e10b18d63bc6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0066ad25d33b26b3a8a2e1bf925c98993a69eaa38e0d4881b6d3e10b18d63bc6", kill_on_drop: false }`
[INFO] [stdout] 0066ad25d33b26b3a8a2e1bf925c98993a69eaa38e0d4881b6d3e10b18d63bc6