[INFO] updating cached repository https://github.com/RedDocMD/huffman
[INFO] running `Command { std: "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", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ac3197a415e59cd288a61746c778d75cff24cb00
[INFO] checking RedDocMD/huffman/ac3197a415e59cd288a61746c778d75cff24cb00 against master#0f6e1ae67854c3c44726e8376144c16b465fe7c6 for pr-129392
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FRedDocMD%2Fhuffman" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/RedDocMD/huffman on toolchain 0f6e1ae67854c3c44726e8376144c16b465fe7c6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+0f6e1ae67854c3c44726e8376144c16b465fe7c6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/RedDocMD/huffman
[INFO] finished tweaking git repo https://github.com/RedDocMD/huffman
[INFO] tweaked toml for git repo https://github.com/RedDocMD/huffman written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/RedDocMD/huffman already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+0f6e1ae67854c3c44726e8376144c16b465fe7c6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+0f6e1ae67854c3c44726e8376144c16b465fe7c6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 08cd3ee0bdf4295bb892aac8a04dbbc1d1e6025524625af4036997a2c7a2a5bc
[INFO] running `Command { std: "docker" "start" "-a" "08cd3ee0bdf4295bb892aac8a04dbbc1d1e6025524625af4036997a2c7a2a5bc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "08cd3ee0bdf4295bb892aac8a04dbbc1d1e6025524625af4036997a2c7a2a5bc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "08cd3ee0bdf4295bb892aac8a04dbbc1d1e6025524625af4036997a2c7a2a5bc", kill_on_drop: false }`
[INFO] [stdout] 08cd3ee0bdf4295bb892aac8a04dbbc1d1e6025524625af4036997a2c7a2a5bc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+0f6e1ae67854c3c44726e8376144c16b465fe7c6" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d4c05d17ac194c99965519431619418dd12507444fc1a4273ac99ef31517b90b
[INFO] running `Command { std: "docker" "start" "-a" "d4c05d17ac194c99965519431619418dd12507444fc1a4273ac99ef31517b90b", kill_on_drop: false }`
[INFO] [stderr]     Checking huffman v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `tree` is never read
[INFO] [stdout]    --> src/lib.rs:166:5
[INFO] [stdout]     |
[INFO] [stdout] 165 | pub struct HuffmanCode {
[INFO] [stdout]     |            ----------- field in this struct
[INFO] [stdout] 166 |     tree: HuffmanCodeTree,
[INFO] [stdout]     |     ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `HuffmanCode` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `tree` is never read
[INFO] [stdout]    --> src/lib.rs:166:5
[INFO] [stdout]     |
[INFO] [stdout] 165 | pub struct HuffmanCode {
[INFO] [stdout]     |            ----------- field in this struct
[INFO] [stdout] 166 |     tree: HuffmanCodeTree,
[INFO] [stdout]     |     ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `HuffmanCode` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.14s
[INFO] running `Command { std: "docker" "inspect" "d4c05d17ac194c99965519431619418dd12507444fc1a4273ac99ef31517b90b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d4c05d17ac194c99965519431619418dd12507444fc1a4273ac99ef31517b90b", kill_on_drop: false }`
[INFO] [stdout] d4c05d17ac194c99965519431619418dd12507444fc1a4273ac99ef31517b90b