[INFO] fetching crate io_utils 0.3.2...
[INFO] checking io_utils-0.3.2 against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] extracting crate io_utils 0.3.2 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate io_utils 0.3.2 on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate io_utils 0.3.2
[INFO] finished tweaking crates.io crate io_utils 0.3.2
[INFO] tweaked toml for crates.io crate io_utils 0.3.2 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 21 packages
[INFO] [stderr]       Adding permutation v0.2.5 (latest: v0.4.1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded string_utils v0.1.4
[INFO] [stderr]   Downloaded permutation v0.2.5
[INFO] [stderr]   Downloaded superslice v1.0.0
[INFO] [stderr]   Downloaded vector_utils v0.1.5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 55911d804d7d69bd201e46cbc494d24d93f2248dcb9ab2693351c1769c5b84c7
[INFO] running `Command { std: "docker" "start" "-a" "55911d804d7d69bd201e46cbc494d24d93f2248dcb9ab2693351c1769c5b84c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "55911d804d7d69bd201e46cbc494d24d93f2248dcb9ab2693351c1769c5b84c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "55911d804d7d69bd201e46cbc494d24d93f2248dcb9ab2693351c1769c5b84c7", kill_on_drop: false }`
[INFO] [stdout] 55911d804d7d69bd201e46cbc494d24d93f2248dcb9ab2693351c1769c5b84c7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9b0d2cbb3b4810305bbf44df85d8f543556595baa8de8513f681f744ec712c94
[INFO] running `Command { std: "docker" "start" "-a" "9b0d2cbb3b4810305bbf44df85d8f543556595baa8de8513f681f744ec712c94", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.197
[INFO] [stderr]     Checking permutation v0.2.5
[INFO] [stderr]     Checking superslice v1.0.0
[INFO] [stderr]    Compiling lz4-sys v1.9.4
[INFO] [stderr]     Checking miniz_oxide v0.7.2
[INFO] [stderr]     Checking vector_utils v0.1.5
[INFO] [stderr]     Checking string_utils v0.1.4
[INFO] [stderr]     Checking flate2 v1.0.28
[INFO] [stderr]     Checking bincode v1.3.3
[INFO] [stderr]     Checking lz4 v1.24.0
[INFO] [stderr]     Checking io_utils v0.3.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `BufRead` is imported redundantly
[INFO] [stdout]   --> src/lib.rs:10:15
[INFO] [stdout]    |
[INFO] [stdout] 10 | use std::io::{BufRead, BufReader};
[INFO] [stdout]    |               ^^^^^^^
[INFO] [stdout] 11 | use std::{fmt::Debug, fs::File, io::prelude::*, path::Path};
[INFO] [stdout]    |                                 -------------- the item `BufRead` is already imported here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `BufRead` is imported redundantly
[INFO] [stdout]   --> src/lib.rs:10:15
[INFO] [stdout]    |
[INFO] [stdout] 10 | use std::io::{BufRead, BufReader};
[INFO] [stdout]    |               ^^^^^^^
[INFO] [stdout] 11 | use std::{fmt::Debug, fs::File, io::prelude::*, path::Path};
[INFO] [stdout]    |                                 -------------- the item `BufRead` is already imported here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[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` profile [unoptimized + debuginfo] target(s) in 9.20s
[INFO] running `Command { std: "docker" "inspect" "9b0d2cbb3b4810305bbf44df85d8f543556595baa8de8513f681f744ec712c94", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9b0d2cbb3b4810305bbf44df85d8f543556595baa8de8513f681f744ec712c94", kill_on_drop: false }`
[INFO] [stdout] 9b0d2cbb3b4810305bbf44df85d8f543556595baa8de8513f681f744ec712c94