[INFO] cloning repository https://github.com/delosrogers/huffman-tree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/delosrogers/huffman-tree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdelosrogers%2Fhuffman-tree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdelosrogers%2Fhuffman-tree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ffdaf17d4ebd2da09f6204d4fa2e15ad8646b167
[INFO] checking delosrogers/huffman-tree against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdelosrogers%2Fhuffman-tree" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/delosrogers/huffman-tree on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/delosrogers/huffman-tree
[INFO] finished tweaking git repo https://github.com/delosrogers/huffman-tree
[INFO] tweaked toml for git repo https://github.com/delosrogers/huffman-tree written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/delosrogers/huffman-tree 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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded partial_application v0.2.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 336ddacc7dfa6d8930e08ff2059636e547fe5fed3c1741ce9074842ab98caee9
[INFO] running `Command { std: "docker" "start" "-a" "336ddacc7dfa6d8930e08ff2059636e547fe5fed3c1741ce9074842ab98caee9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "336ddacc7dfa6d8930e08ff2059636e547fe5fed3c1741ce9074842ab98caee9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "336ddacc7dfa6d8930e08ff2059636e547fe5fed3c1741ce9074842ab98caee9", kill_on_drop: false }`
[INFO] [stdout] 336ddacc7dfa6d8930e08ff2059636e547fe5fed3c1741ce9074842ab98caee9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c8fc13d022b3af63d430381086415e06df8ef2c05d7586bc2076aa954450aac3
[INFO] running `Command { std: "docker" "start" "-a" "c8fc13d022b3af63d430381086415e06df8ef2c05d7586bc2076aa954450aac3", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.88
[INFO] [stderr]    Compiling syn v1.0.64
[INFO] [stderr]    Compiling crossbeam-utils v0.8.3
[INFO] [stderr]    Compiling memoffset v0.6.1
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling serde_derive v1.0.124
[INFO] [stderr]    Compiling rayon-core v1.9.0
[INFO] [stderr]    Compiling unicode-segmentation v1.7.1
[INFO] [stderr]    Compiling serde v1.0.124
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling rayon v1.5.0
[INFO] [stderr]     Checking ppv-lite86 v0.2.10
[INFO] [stderr]    Compiling heck v0.3.2
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]     Checking partial_application v0.2.1
[INFO] [stderr]     Checking crossbeam-epoch v0.9.3
[INFO] [stderr]     Checking crossbeam-channel v0.5.0
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking crossbeam-deque v0.8.0
[INFO] [stderr]     Checking rand_core v0.6.2
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking rand v0.8.3
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling structopt-derive v0.4.14
[INFO] [stderr]     Checking structopt v0.3.21
[INFO] [stderr]     Checking serde_json v1.0.64
[INFO] [stderr]     Checking mzip v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `String` is imported redundantly
[INFO] [stdout]  --> src/decode.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::string::String;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `String` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `String` is imported redundantly
[INFO] [stdout]  --> src/encode.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::string::String;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `String` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]   --> src/main.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 11 | use serde_json;
[INFO] [stdout]    |     ^^^^^^^^^^ the item `serde_json` is already defined by prelude
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `String` is imported redundantly
[INFO] [stdout]   --> src/main.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | use std::string::String;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]    |
[INFO] [stdout]    = note: the item `String` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `String` is imported redundantly
[INFO] [stdout]  --> src/decode.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::string::String;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `String` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `String` is imported redundantly
[INFO] [stdout]  --> src/encode.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::string::String;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `String` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]   --> src/main.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 11 | use serde_json;
[INFO] [stdout]    |     ^^^^^^^^^^ the item `serde_json` is already defined by prelude
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `String` is imported redundantly
[INFO] [stdout]   --> src/main.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 | use std::string::String;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:134:13
[INFO] [stdout]    |
[INFO] [stdout]    = note: the item `String` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 25.86s
[INFO] running `Command { std: "docker" "inspect" "c8fc13d022b3af63d430381086415e06df8ef2c05d7586bc2076aa954450aac3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c8fc13d022b3af63d430381086415e06df8ef2c05d7586bc2076aa954450aac3", kill_on_drop: false }`
[INFO] [stdout] c8fc13d022b3af63d430381086415e06df8ef2c05d7586bc2076aa954450aac3