[INFO] updating cached repository https://github.com/Nalleyer/rust_99_problem
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/mnt/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 963a80b26b71b2cb375922c8d99b1096e715d0e5
[INFO] checking Nalleyer/rust_99_problem against master#c9edc02e8320a9e5799d185910ece7d491f524e6 for pr-64398
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2FNalleyer%2Frust_99_problem" "work/builds/worker-4/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Nalleyer/rust_99_problem on toolchain c9edc02e8320a9e5799d185910ece7d491f524e6-alt
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/Nalleyer/rust_99_problem
[INFO] finished tweaking git repo https://github.com/Nalleyer/rust_99_problem
[INFO] tweaked toml for git repo https://github.com/Nalleyer/rust_99_problem written to work/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/Nalleyer/rust_99_problem already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/mnt/big/crater/work/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/mnt/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 8456ed7577967ce95debf2aa236ca99369e491815319d36bc56afc19cd87c673
[INFO] running `"docker" "start" "-a" "8456ed7577967ce95debf2aa236ca99369e491815319d36bc56afc19cd87c673"`
[INFO] [stderr]    Compiling syn v0.15.29
[INFO] [stderr]     Checking env_logger v0.6.1
[INFO] [stderr]     Checking quickcheck v0.8.2
[INFO] [stderr]    Compiling quickcheck_macros v0.8.0
[INFO] [stderr]     Checking rust_99_problem v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused `#[macro_use]` import
[INFO] [stderr]  --> src/main.rs:4:13
[INFO] [stderr]   |
[INFO] [stderr] 4 | #[macro_use(quickcheck)]
[INFO] [stderr]   |             ^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/solves/p7.rs:14:24
[INFO] [stderr]    |
[INFO] [stderr] 14 |             Node::Item(x) => vec!(node.clone()),
[INFO] [stderr]    |                        ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `is_item`
[INFO] [stderr]   --> src/common.rs:14:13
[INFO] [stderr]    |
[INFO] [stderr] 14 |         let is_item: bool = g.gen();
[INFO] [stderr]    |             ^^^^^^^ help: consider prefixing with an underscore: `_is_item`
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `flat`
[INFO] [stderr]   --> src/solves/p7.rs:11:1
[INFO] [stderr]    |
[INFO] [stderr] 11 | pub fn flat<T: Clone>(ls: &List<T>) -> List<T> {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/solves/p7.rs:14:24
[INFO] [stderr]    |
[INFO] [stderr] 14 |             Node::Item(x) => vec!(node.clone()),
[INFO] [stderr]    |                        ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `is_item`
[INFO] [stderr]   --> src/common.rs:14:13
[INFO] [stderr]    |
[INFO] [stderr] 14 |         let is_item: bool = g.gen();
[INFO] [stderr]    |             ^^^^^^^ help: consider prefixing with an underscore: `_is_item`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 20.14s
[INFO] running `"docker" "inspect" "8456ed7577967ce95debf2aa236ca99369e491815319d36bc56afc19cd87c673"`
[INFO] running `"docker" "rm" "-f" "8456ed7577967ce95debf2aa236ca99369e491815319d36bc56afc19cd87c673"`
[INFO] [stdout] 8456ed7577967ce95debf2aa236ca99369e491815319d36bc56afc19cd87c673