[INFO] cloning repository https://github.com/howeih/Day-14-Huffman-codes
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/howeih/Day-14-Huffman-codes" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhoweih%2FDay-14-Huffman-codes", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhoweih%2FDay-14-Huffman-codes'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 65a14d8fffeb7cd8a8ef5c8b78f23847140c1d84
[INFO] checking howeih/Day-14-Huffman-codes against master#32c26302620b2dbbe0a2291f1969bc0b1622ae59 for pr-95755
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhoweih%2FDay-14-Huffman-codes" "/workspace/builds/worker-109/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-109/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/howeih/Day-14-Huffman-codes on toolchain 32c26302620b2dbbe0a2291f1969bc0b1622ae59
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+32c26302620b2dbbe0a2291f1969bc0b1622ae59" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/howeih/Day-14-Huffman-codes
[INFO] finished tweaking git repo https://github.com/howeih/Day-14-Huffman-codes
[INFO] tweaked toml for git repo https://github.com/howeih/Day-14-Huffman-codes written to /workspace/builds/worker-109/source/Cargo.toml
[INFO] crate git repo https://github.com/howeih/Day-14-Huffman-codes already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+32c26302620b2dbbe0a2291f1969bc0b1622ae59" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-109/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-109/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+32c26302620b2dbbe0a2291f1969bc0b1622ae59" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 77100ade17c0616bf828a7f6d07512630cb3e96c094dbdbac7fc185299185fb3
[INFO] running `Command { std: "docker" "start" "-a" "77100ade17c0616bf828a7f6d07512630cb3e96c094dbdbac7fc185299185fb3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "77100ade17c0616bf828a7f6d07512630cb3e96c094dbdbac7fc185299185fb3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "77100ade17c0616bf828a7f6d07512630cb3e96c094dbdbac7fc185299185fb3", kill_on_drop: false }`
[INFO] [stdout] 77100ade17c0616bf828a7f6d07512630cb3e96c094dbdbac7fc185299185fb3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-109/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-109/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" "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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+32c26302620b2dbbe0a2291f1969bc0b1622ae59" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4f468aae23e4b7fb3b87a8c04d8b40f7499ff5e0a8bd7f0d15e892e6e9232fca
[INFO] running `Command { std: "docker" "start" "-a" "4f468aae23e4b7fb3b87a8c04d8b40f7499ff5e0a8bd7f0d15e892e6e9232fca", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking huffman_codes v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `node_id`
[INFO] [stdout]   --> src/main.rs:16:5
[INFO] [stdout]    |
[INFO] [stdout] 16 |     node_id: i32,
[INFO] [stdout]    |     ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   --> src/main.rs:14:10
[INFO] [stdout]    |
[INFO] [stdout] 14 | #[derive(Debug)]
[INFO] [stdout]    |          ^^^^^
[INFO] [stdout]    = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `node_id`
[INFO] [stdout]   --> src/main.rs:16:5
[INFO] [stdout]    |
[INFO] [stdout] 16 |     node_id: i32,
[INFO] [stdout]    |     ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   --> src/main.rs:14:10
[INFO] [stdout]    |
[INFO] [stdout] 14 | #[derive(Debug)]
[INFO] [stdout]    |          ^^^^^
[INFO] [stdout]    = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.34s
[INFO] running `Command { std: "docker" "inspect" "4f468aae23e4b7fb3b87a8c04d8b40f7499ff5e0a8bd7f0d15e892e6e9232fca", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4f468aae23e4b7fb3b87a8c04d8b40f7499ff5e0a8bd7f0d15e892e6e9232fca", kill_on_drop: false }`
[INFO] [stdout] 4f468aae23e4b7fb3b87a8c04d8b40f7499ff5e0a8bd7f0d15e892e6e9232fca