[INFO] updating cached repository https://github.com/ethowitz/life
[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] ed6ce81d54be37f00fcdb639475c3cdcd1c1c598
[INFO] checking ethowitz/life against master#c9edc02e8320a9e5799d185910ece7d491f524e6 for pr-64398
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fethowitz%2Flife" "work/builds/worker-0/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ethowitz/life 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/ethowitz/life
[INFO] finished tweaking git repo https://github.com/ethowitz/life
[INFO] tweaked toml for git repo https://github.com/ethowitz/life written to work/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/ethowitz/life 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-0/target:/opt/rustwide/target:rw,Z" "-v" "/mnt/big/crater/work/builds/worker-0/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] 040d52a75b5134623fe2d81201fed94e176f1f282e426f82399a59eb48401868
[INFO] running `"docker" "start" "-a" "040d52a75b5134623fe2d81201fed94e176f1f282e426f82399a59eb48401868"`
[INFO] [stderr]     Checking life v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:55:21
[INFO] [stderr]    |
[INFO] [stderr] 55 |     let gen_char = |x| if rand::random::<i64>() % 4 == 1 {ALIVE} else {' '};
[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[E0506]: cannot assign to `*row` because it is borrowed
[INFO] [stderr]   --> src/main.rs:57:9
[INFO] [stderr]    |
[INFO] [stderr] 57 |         *row = row.into_iter().map(&gen_char).collect();
[INFO] [stderr]    |         ^^^^   ---                 --------- borrow later used here
[INFO] [stderr]    |         |      |
[INFO] [stderr]    |         |      borrow of `*row` occurs here
[INFO] [stderr]    |         assignment to borrowed `*row` occurs here
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this error has been downgraded to a warning for backwards compatibility with previous releases
[INFO] [stderr]    = warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
[INFO] [stderr]    = note: for more information, try `rustc --explain E0729`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:55:21
[INFO] [stderr]    |
[INFO] [stderr] 55 |     let gen_char = |x| if rand::random::<i64>() % 4 == 1 {ALIVE} else {' '};
[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[E0506]: cannot assign to `*row` because it is borrowed
[INFO] [stderr]   --> src/main.rs:57:9
[INFO] [stderr]    |
[INFO] [stderr] 57 |         *row = row.into_iter().map(&gen_char).collect();
[INFO] [stderr]    |         ^^^^   ---                 --------- borrow later used here
[INFO] [stderr]    |         |      |
[INFO] [stderr]    |         |      borrow of `*row` occurs here
[INFO] [stderr]    |         assignment to borrowed `*row` occurs here
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this error has been downgraded to a warning for backwards compatibility with previous releases
[INFO] [stderr]    = warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
[INFO] [stderr]    = note: for more information, try `rustc --explain E0729`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.93s
[INFO] running `"docker" "inspect" "040d52a75b5134623fe2d81201fed94e176f1f282e426f82399a59eb48401868"`
[INFO] running `"docker" "rm" "-f" "040d52a75b5134623fe2d81201fed94e176f1f282e426f82399a59eb48401868"`
[INFO] [stdout] 040d52a75b5134623fe2d81201fed94e176f1f282e426f82399a59eb48401868