[INFO] updating cached repository https://github.com/swizzard/boggler
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/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] cc01442ec61024df5448d8460f06d2fcdd7e2531
[INFO] checking swizzard/boggler against master#2748a9fd93dd1a00a4521f4f16de5befbf77f6cd for pr-62262-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fswizzard%2Fboggler" "/workspace/builds/worker-0/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/swizzard/boggler on toolchain 2748a9fd93dd1a00a4521f4f16de5befbf77f6cd
[INFO] running `"/workspace/cargo-home/bin/cargo" "+2748a9fd93dd1a00a4521f4f16de5befbf77f6cd" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/swizzard/boggler
[INFO] finished tweaking git repo https://github.com/swizzard/boggler
[INFO] tweaked toml for git repo https://github.com/swizzard/boggler written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/swizzard/boggler already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+2748a9fd93dd1a00a4521f4f16de5befbf77f6cd" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/source:/opt/rustwide/workdir:ro,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" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-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" "+2748a9fd93dd1a00a4521f4f16de5befbf77f6cd" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 660408c8ab8598da955fe040015182088e09fac5c738d64718914a40ce719040
[INFO] running `"docker" "start" "-a" "660408c8ab8598da955fe040015182088e09fac5c738d64718914a40ce719040"`
[INFO] [stderr]     Checking rand_core v0.2.1
[INFO] [stderr]     Checking ascii v0.8.7
[INFO] [stderr]     Checking atty v0.2.10
[INFO] [stderr]     Checking textwrap v0.9.0
[INFO] [stderr]     Checking clap v2.31.2
[INFO] [stderr]     Checking rand v0.5.1
[INFO] [stderr]     Checking boggler v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused variable: `seen`
[INFO] [stderr]    --> src/solver.rs:156:17
[INFO] [stderr]     |
[INFO] [stderr] 156 |         let mut seen: HashSet<BoardPosition> = HashSet::with_capacity(16);
[INFO] [stderr]     |                 ^^^^ help: consider prefixing with an underscore: `_seen`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `adjcts`
[INFO] [stderr]    --> src/solver.rs:158:17
[INFO] [stderr]     |
[INFO] [stderr] 158 |             let adjcts = board.adjacents(x, y);
[INFO] [stderr]     |                 ^^^^^^ help: consider prefixing with an underscore: `_adjcts`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/solver.rs:154:13
[INFO] [stderr]     |
[INFO] [stderr] 154 |         let mut x = 0;
[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/solver.rs:155:13
[INFO] [stderr]     |
[INFO] [stderr] 155 |         let mut y = 0;
[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/solver.rs:156:13
[INFO] [stderr]     |
[INFO] [stderr] 156 |         let mut seen: HashSet<BoardPosition> = HashSet::with_capacity(16);
[INFO] [stderr]     |             ----^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `find_letter`
[INFO] [stderr]    --> src/solver.rs:149:5
[INFO] [stderr]     |
[INFO] [stderr] 149 |     fn find_letter(&self, chr: &AsciiChar) -> Option<&BTNode> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] warning: unused variable: `seen`
[INFO] [stderr]    --> src/solver.rs:156:17
[INFO] [stderr]     |
[INFO] [stderr] 156 |         let mut seen: HashSet<BoardPosition> = HashSet::with_capacity(16);
[INFO] [stderr]     |                 ^^^^ help: consider prefixing with an underscore: `_seen`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `adjcts`
[INFO] [stderr]    --> src/solver.rs:158:17
[INFO] [stderr]     |
[INFO] [stderr] 158 |             let adjcts = board.adjacents(x, y);
[INFO] [stderr]     |                 ^^^^^^ help: consider prefixing with an underscore: `_adjcts`
[INFO] [stderr] 
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/solver.rs:154:13
[INFO] [stderr]     |
[INFO] [stderr] 154 |         let mut x = 0;
[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/solver.rs:155:13
[INFO] [stderr]     |
[INFO] [stderr] 155 |         let mut y = 0;
[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/solver.rs:156:13
[INFO] [stderr]     |
[INFO] [stderr] 156 |         let mut seen: HashSet<BoardPosition> = HashSet::with_capacity(16);
[INFO] [stderr]     |             ----^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.22s
[INFO] running `"docker" "inspect" "660408c8ab8598da955fe040015182088e09fac5c738d64718914a40ce719040"`
[INFO] running `"docker" "rm" "-f" "660408c8ab8598da955fe040015182088e09fac5c738d64718914a40ce719040"`
[INFO] [stdout] 660408c8ab8598da955fe040015182088e09fac5c738d64718914a40ce719040