[INFO] updating cached repository https://github.com/mjl152/rust-euler
[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] cf3eed55ee1ace81d88f24764707341ef0df4aa7
[INFO] checking mjl152/rust-euler against master#c9edc02e8320a9e5799d185910ece7d491f524e6 for pr-64398
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmjl152%2Frust-euler" "work/builds/worker-3/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mjl152/rust-euler 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/mjl152/rust-euler
[INFO] finished tweaking git repo https://github.com/mjl152/rust-euler
[INFO] tweaked toml for git repo https://github.com/mjl152/rust-euler written to work/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/mjl152/rust-euler 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] [stderr] error: the lock file /mnt/big/crater/work/builds/worker-3/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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-3/target:/opt/rustwide/target:rw,Z" "-v" "/mnt/big/crater/work/builds/worker-3/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] ec7e8917900d0fe5dad2b7d0c7b5d7db44881035bad94dcb7c35e0ab8ac3d9a9
[INFO] running `"docker" "start" "-a" "ec7e8917900d0fe5dad2b7d0c7b5d7db44881035bad94dcb7c35e0ab8ac3d9a9"`
[INFO] [stderr]     Checking rust_euler v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]   --> src/main.rs:47:6
[INFO] [stderr]    |
[INFO] [stderr] 47 |     for i in 0..iterations {
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_i`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:33:6
[INFO] [stderr]    |
[INFO] [stderr] 33 |     let mut problem : fn() -> Option<u64>;
[INFO] [stderr]    |         ----^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]   --> src/main.rs:47:6
[INFO] [stderr]    |
[INFO] [stderr] 47 |     for i in 0..iterations {
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_i`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:33:6
[INFO] [stderr]    |
[INFO] [stderr] 33 |     let mut problem : fn() -> Option<u64>;
[INFO] [stderr]    |         ----^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.35s
[INFO] running `"docker" "inspect" "ec7e8917900d0fe5dad2b7d0c7b5d7db44881035bad94dcb7c35e0ab8ac3d9a9"`
[INFO] running `"docker" "rm" "-f" "ec7e8917900d0fe5dad2b7d0c7b5d7db44881035bad94dcb7c35e0ab8ac3d9a9"`
[INFO] [stdout] ec7e8917900d0fe5dad2b7d0c7b5d7db44881035bad94dcb7c35e0ab8ac3d9a9