[INFO] cloning repository https://github.com/BenSandeen/sudoku-hinter-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/BenSandeen/sudoku-hinter-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBenSandeen%2Fsudoku-hinter-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBenSandeen%2Fsudoku-hinter-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 26b144748206c8ee57b1e6d9dc80d48635ac9aaa
[INFO] checking BenSandeen/sudoku-hinter-rs against master#5e3f1b148db5bfa27fee52464ae1f5d34c49d77b for pr-75502
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBenSandeen%2Fsudoku-hinter-rs" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/BenSandeen/sudoku-hinter-rs on toolchain 5e3f1b148db5bfa27fee52464ae1f5d34c49d77b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/BenSandeen/sudoku-hinter-rs
[INFO] finished tweaking git repo https://github.com/BenSandeen/sudoku-hinter-rs
[INFO] tweaked toml for git repo https://github.com/BenSandeen/sudoku-hinter-rs written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/BenSandeen/sudoku-hinter-rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "metadata" "--no-deps" "--format-version=1", 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] 0962a548c7afca7f3f6af59bb4196240997e66b31451fed742a598c6a8a5c1ce
[INFO] running `Command { std: "docker" "start" "-a" "0962a548c7afca7f3f6af59bb4196240997e66b31451fed742a598c6a8a5c1ce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0962a548c7afca7f3f6af59bb4196240997e66b31451fed742a598c6a8a5c1ce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0962a548c7afca7f3f6af59bb4196240997e66b31451fed742a598c6a8a5c1ce", kill_on_drop: false }`
[INFO] [stdout] 0962a548c7afca7f3f6af59bb4196240997e66b31451fed742a598c6a8a5c1ce
[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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 183e8fa431c5d3ec53934b28be494c9bb15b04b055f9b3beae49117569c12fcb
[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" "183e8fa431c5d3ec53934b28be494c9bb15b04b055f9b3beae49117569c12fcb", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.38
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling serde v1.0.115
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking ppv-lite86 v0.2.8
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking csv-core v0.1.10
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]    Compiling serde_derive v1.0.115
[INFO] [stderr]     Checking bstr v0.2.13
[INFO] [stderr]     Checking csv v1.1.3
[INFO] [stderr]     Checking sudoku-hinter-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `BorrowMut`
[INFO] [stdout]  --> src/main.rs:2:19
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::borrow::{BorrowMut, Borrow};
[INFO] [stdout]   |                   ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let mut rng = rand::thread_rng();
[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: unused import: `BorrowMut`
[INFO] [stdout]  --> src/main.rs:2:19
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::borrow::{BorrowMut, Borrow};
[INFO] [stdout]   |                   ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `has_unique_elements`
[INFO] [stdout]   --> src/main.rs:39:4
[INFO] [stdout]    |
[INFO] [stdout] 39 | fn has_unique_elements<T>(iter: T) -> bool
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `check_intermediate_puzzle`
[INFO] [stdout]    --> src/main.rs:204:8
[INFO] [stdout]     |
[INFO] [stdout] 204 |     fn check_intermediate_puzzle(&self, last_modified_cell: Cell) -> bool {
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let mut rng = rand::thread_rng();
[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: function is never used: `has_unique_elements`
[INFO] [stdout]   --> src/main.rs:39:4
[INFO] [stdout]    |
[INFO] [stdout] 39 | fn has_unique_elements<T>(iter: T) -> bool
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `check_intermediate_puzzle`
[INFO] [stdout]    --> src/main.rs:204:8
[INFO] [stdout]     |
[INFO] [stdout] 204 |     fn check_intermediate_puzzle(&self, last_modified_cell: Cell) -> bool {
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 39.58s
[INFO] running `Command { std: "docker" "inspect" "183e8fa431c5d3ec53934b28be494c9bb15b04b055f9b3beae49117569c12fcb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "183e8fa431c5d3ec53934b28be494c9bb15b04b055f9b3beae49117569c12fcb", kill_on_drop: false }`
[INFO] [stdout] 183e8fa431c5d3ec53934b28be494c9bb15b04b055f9b3beae49117569c12fcb