[INFO] cloning repository https://github.com/trickypr/huffman-coding
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/trickypr/huffman-coding" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftrickypr%2Fhuffman-coding", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftrickypr%2Fhuffman-coding'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 34414e9ee0e6569b390e3457071e6fb905494d75
[INFO] checking trickypr/huffman-coding against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftrickypr%2Fhuffman-coding" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/trickypr/huffman-coding on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/trickypr/huffman-coding
[INFO] finished tweaking git repo https://github.com/trickypr/huffman-coding
[INFO] tweaked toml for git repo https://github.com/trickypr/huffman-coding written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/trickypr/huffman-coding already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--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-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 84baf41b51a8fc18cbf91b1b221ca652add482dc22fc7815d1f39ade0bf0c16b
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "84baf41b51a8fc18cbf91b1b221ca652add482dc22fc7815d1f39ade0bf0c16b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "84baf41b51a8fc18cbf91b1b221ca652add482dc22fc7815d1f39ade0bf0c16b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "84baf41b51a8fc18cbf91b1b221ca652add482dc22fc7815d1f39ade0bf0c16b", kill_on_drop: false }`
[INFO] [stdout] 84baf41b51a8fc18cbf91b1b221ca652add482dc22fc7815d1f39ade0bf0c16b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 2ecd6e8d166a173a455bc3c07c5163b841c93f00617460133edba87104303a4c
[INFO] running `Command { std: "docker" "start" "-a" "2ecd6e8d166a173a455bc3c07c5163b841c93f00617460133edba87104303a4c", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.21
[INFO] [stderr]    Compiling syn v1.0.40
[INFO] [stderr]    Compiling serde_derive v1.0.115
[INFO] [stderr]    Compiling serde v1.0.115
[INFO] [stderr]    Compiling serde_json v1.0.57
[INFO] [stderr]     Checking itoa v0.4.6
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]     Checking huffman-coding v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `iter::FromIterator`
[INFO] [stdout]  --> src/main.rs:1:52
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{fs, fs::File, io::prelude::*, io::Error, iter::FromIterator, path::Path};
[INFO] [stdout]   |                                                    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `generate_tree`, `utils::bits_to_bytes`
[INFO] [stdout]  --> src/main.rs:6:29
[INFO] [stdout]   |
[INFO] [stdout] 6 |     compression::{compress, generate_tree},
[INFO] [stdout]   |                             ^^^^^^^^^^^^^
[INFO] [stdout] 7 |     decompression::decompress,
[INFO] [stdout] 8 |     utils::bits_to_bytes,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `iter::FromIterator`
[INFO] [stdout]  --> src/main.rs:1:52
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{fs, fs::File, io::prelude::*, io::Error, iter::FromIterator, path::Path};
[INFO] [stdout]   |                                                    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `generate_tree`, `utils::bits_to_bytes`
[INFO] [stdout]  --> src/main.rs:6:29
[INFO] [stdout]   |
[INFO] [stdout] 6 |     compression::{compress, generate_tree},
[INFO] [stdout]   |                             ^^^^^^^^^^^^^
[INFO] [stdout] 7 |     decompression::decompress,
[INFO] [stdout] 8 |     utils::bits_to_bytes,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 32.23s
[INFO] running `Command { std: "docker" "inspect" "2ecd6e8d166a173a455bc3c07c5163b841c93f00617460133edba87104303a4c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2ecd6e8d166a173a455bc3c07c5163b841c93f00617460133edba87104303a4c", kill_on_drop: false }`
[INFO] [stdout] 2ecd6e8d166a173a455bc3c07c5163b841c93f00617460133edba87104303a4c