[INFO] cloning repository https://github.com/connesc/sudoku-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/connesc/sudoku-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fconnesc%2Fsudoku-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fconnesc%2Fsudoku-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0088c8377ff84527a1d49db816f17b883deb5df5
[INFO] checking connesc/sudoku-rs against 40527f3e444fde1deb361751bdef9b9e11d1b971+rustflags=--cfg crater_hack --force-warn invalid-c-variadic-arguments for pr-162478
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fconnesc%2Fsudoku-rs" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/connesc/sudoku-rs
[INFO] finished tweaking git repo https://github.com/connesc/sudoku-rs
[INFO] tweaked toml for git repo https://github.com/connesc/sudoku-rs written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/connesc/sudoku-rs on toolchain 40527f3e444fde1deb361751bdef9b9e11d1b971
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+40527f3e444fde1deb361751bdef9b9e11d1b971" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/connesc/sudoku-rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+40527f3e444fde1deb361751bdef9b9e11d1b971" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: explicit `package.readme` can be inferred
[INFO] [stderr]  --> Cargo.toml:9:1
[INFO] [stderr]   |
[INFO] [stderr] 9 | readme = "README.md"
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `cargo::manual_readme` is set to `warn` by default
[INFO] [stderr] help: consider removing `package.readme`
[INFO] [stderr] warning: `sudoku` (manifest) generated 1 warning
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded getrandom v0.2.2
[INFO] [stderr]   Downloaded rand_core v0.6.1
[INFO] [stderr]   Downloaded libc v0.2.84
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,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" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:8683fc1fc2eb5c9ac98e0d076ab094b2ffac7f99da555d2b6a2e27f346de2ec7" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] 17e69be5de174f9d8582900426a621b8bb77d4a4753f1c82c7144604f4cba926
[INFO] running `Command { std: "docker" "start" "17e69be5de174f9d8582900426a621b8bb77d4a4753f1c82c7144604f4cba926", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "17e69be5de174f9d8582900426a621b8bb77d4a4753f1c82c7144604f4cba926", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "17e69be5de174f9d8582900426a621b8bb77d4a4753f1c82c7144604f4cba926" "/opt/rustwide/cargo-home/bin/cargo" "+40527f3e444fde1deb361751bdef9b9e11d1b971" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "17e69be5de174f9d8582900426a621b8bb77d4a4753f1c82c7144604f4cba926", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid --cfg crater_hack --force-warn invalid-c-variadic-arguments" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-w" "/opt/rustwide/workdir" "--user" "0:0" "17e69be5de174f9d8582900426a621b8bb77d4a4753f1c82c7144604f4cba926" "/opt/rustwide/cargo-home/bin/cargo" "+40527f3e444fde1deb361751bdef9b9e11d1b971" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] warning: explicit `package.readme` can be inferred
[INFO] [stderr]  --> Cargo.toml:9:1
[INFO] [stderr]   |
[INFO] [stderr] 9 | readme = "README.md"
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `cargo::manual_readme` is set to `warn` by default
[INFO] [stderr] help: consider removing `package.readme`
[INFO] [stderr] warning: `sudoku` (manifest) generated 1 warning
[INFO] [stderr]    Compiling libc v0.2.84
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]     Checking rand_core v0.6.1
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking rand v0.8.3
[INFO] [stderr]     Checking sudoku v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:335:5
[INFO] [stdout]     |
[INFO] [stdout] 335 |     &mut items[..len].shuffle(rng);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 335 |     let _ = &mut items[..len].shuffle(rng);
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/lib.rs:445:18
[INFO] [stdout]     |
[INFO] [stdout] 445 |     fn new(grid: &mut Grid) -> Solver {
[INFO] [stdout]     |                  ^^^^^^^^^     ^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                  |
[INFO] [stdout]     |                  the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 445 |     fn new(grid: &mut Grid) -> Solver<'_> {
[INFO] [stdout]     |                                      ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:335:5
[INFO] [stdout]     |
[INFO] [stdout] 335 |     &mut items[..len].shuffle(rng);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 335 |     let _ = &mut items[..len].shuffle(rng);
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/lib.rs:445:18
[INFO] [stdout]     |
[INFO] [stdout] 445 |     fn new(grid: &mut Grid) -> Solver {
[INFO] [stdout]     |                  ^^^^^^^^^     ^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                  |
[INFO] [stdout]     |                  the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 445 |     fn new(grid: &mut Grid) -> Solver<'_> {
[INFO] [stdout]     |                                      ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.92s
[INFO] running `Command { std: "docker" "inspect" "17e69be5de174f9d8582900426a621b8bb77d4a4753f1c82c7144604f4cba926", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "17e69be5de174f9d8582900426a621b8bb77d4a4753f1c82c7144604f4cba926", kill_on_drop: false }`
[INFO] [stdout] 17e69be5de174f9d8582900426a621b8bb77d4a4753f1c82c7144604f4cba926
