[INFO] updating cached repository https://github.com/ntedeschi/systems
[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] a3326d67f88169e07da5d54333db36860b0ac5f5
[INFO] checking ntedeschi/systems against master#c9edc02e8320a9e5799d185910ece7d491f524e6 for pr-64398
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fntedeschi%2Fsystems" "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/ntedeschi/systems 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/ntedeschi/systems
[INFO] finished tweaking git repo https://github.com/ntedeschi/systems
[INFO] tweaked toml for git repo https://github.com/ntedeschi/systems written to work/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/ntedeschi/systems 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-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] 1f39be095097bc0b20ed57110c900bd10b8f82f6779c6f7d317c2966eeab5dd4
[INFO] running `"docker" "start" "-a" "1f39be095097bc0b20ed57110c900bd10b8f82f6779c6f7d317c2966eeab5dd4"`
[INFO] [stderr]     Checking systems v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]  --> src/ch02/prac.rs:5:9
[INFO] [stderr]   |
[INFO] [stderr] 5 |     let mut f = ".01110";
[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: variable does not need to be mutable
[INFO] [stderr]  --> src/ch02/prac.rs:6:9
[INFO] [stderr]   |
[INFO] [stderr] 6 |     let mut x = fractional_binary_to_decimal(f);
[INFO] [stderr]   |         ----^
[INFO] [stderr]   |         |
[INFO] [stderr]   |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]  --> src/ch02/prac.rs:5:9
[INFO] [stderr]   |
[INFO] [stderr] 5 |     let mut f = ".01110";
[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: variable does not need to be mutable
[INFO] [stderr]  --> src/ch02/prac.rs:6:9
[INFO] [stderr]   |
[INFO] [stderr] 6 |     let mut x = fractional_binary_to_decimal(f);
[INFO] [stderr]   |         ----^
[INFO] [stderr]   |         |
[INFO] [stderr]   |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.25s
[INFO] running `"docker" "inspect" "1f39be095097bc0b20ed57110c900bd10b8f82f6779c6f7d317c2966eeab5dd4"`
[INFO] running `"docker" "rm" "-f" "1f39be095097bc0b20ed57110c900bd10b8f82f6779c6f7d317c2966eeab5dd4"`
[INFO] [stdout] 1f39be095097bc0b20ed57110c900bd10b8f82f6779c6f7d317c2966eeab5dd4