[INFO] fetching crate byte-mutator 0.2.0...
[INFO] checking byte-mutator-0.2.0 against try#cac44d9528e3bbbdaa1537d187bd489ccc5de18c for pr-91141
[INFO] extracting crate byte-mutator 0.2.0 into /workspace/builds/worker-54/source
[INFO] validating manifest of crates.io crate byte-mutator 0.2.0 on toolchain cac44d9528e3bbbdaa1537d187bd489ccc5de18c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate byte-mutator 0.2.0
[INFO] finished tweaking crates.io crate byte-mutator 0.2.0
[INFO] tweaked toml for crates.io crate byte-mutator 0.2.0 written to /workspace/builds/worker-54/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5fa41a4f9c094eb0fd3a143ff9c3b76e13784f46083e4ab2dbdf556de4d735c7
[INFO] running `Command { std: "docker" "start" "-a" "5fa41a4f9c094eb0fd3a143ff9c3b76e13784f46083e4ab2dbdf556de4d735c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5fa41a4f9c094eb0fd3a143ff9c3b76e13784f46083e4ab2dbdf556de4d735c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5fa41a4f9c094eb0fd3a143ff9c3b76e13784f46083e4ab2dbdf556de4d735c7", kill_on_drop: false }`
[INFO] [stdout] 5fa41a4f9c094eb0fd3a143ff9c3b76e13784f46083e4ab2dbdf556de4d735c7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c549b4de05ec435704bb4988c9a0f7e37fe57d98f770feea80df3fd192803ee9
[INFO] running `Command { std: "docker" "start" "-a" "c549b4de05ec435704bb4988c9a0f7e37fe57d98f770feea80df3fd192803ee9", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v1.0.82
[INFO] [stderr]    Compiling serde v1.0.130
[INFO] [stderr]    Compiling serde_derive v1.0.130
[INFO] [stderr]     Checking toml v0.5.8
[INFO] [stderr]     Checking byte-mutator v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Iterations`
[INFO] [stdout]  --> src/fuzz_config.rs:5:13
[INFO] [stdout]   |
[INFO] [stdout] 5 | use crate::{Iterations, Stage};
[INFO] [stdout]   |             ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Iterations`
[INFO] [stdout]  --> src/fuzz_config.rs:5:13
[INFO] [stdout]   |
[INFO] [stdout] 5 | use crate::{Iterations, Stage};
[INFO] [stdout]   |             ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `cur_stage`
[INFO] [stdout]   --> src/lib.rs:86:5
[INFO] [stdout]    |
[INFO] [stdout] 86 |     cur_stage: usize,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `cur_stage`
[INFO] [stdout]   --> src/lib.rs:86:5
[INFO] [stdout]    |
[INFO] [stdout] 86 |     cur_stage: usize,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> tests/tests.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let mut mutator = ByteMutator::new().with_stages(vec![Stage {
[INFO] [stdout]    |         ----^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 14.51s
[INFO] running `Command { std: "docker" "inspect" "c549b4de05ec435704bb4988c9a0f7e37fe57d98f770feea80df3fd192803ee9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c549b4de05ec435704bb4988c9a0f7e37fe57d98f770feea80df3fd192803ee9", kill_on_drop: false }`
[INFO] [stdout] c549b4de05ec435704bb4988c9a0f7e37fe57d98f770feea80df3fd192803ee9