[INFO] cloning repository https://github.com/ElectricCoffee/word_generator
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ElectricCoffee/word_generator" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FElectricCoffee%2Fword_generator", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FElectricCoffee%2Fword_generator'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8066370286e040f0e85b5648677089f10e82d6bc
[INFO] checking ElectricCoffee/word_generator against master#dfd7b8d03fb93d0e03147d28b3be6d93260fa94d for pr-87050
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FElectricCoffee%2Fword_generator" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ElectricCoffee/word_generator on toolchain dfd7b8d03fb93d0e03147d28b3be6d93260fa94d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ElectricCoffee/word_generator
[INFO] finished tweaking git repo https://github.com/ElectricCoffee/word_generator
[INFO] tweaked toml for git repo https://github.com/ElectricCoffee/word_generator written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/ElectricCoffee/word_generator already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "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-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cfd00de97b591eebbd27bc2c4dd413e1f25bf5c48ff4547470e28effdd4646c2
[INFO] running `Command { std: "docker" "start" "-a" "cfd00de97b591eebbd27bc2c4dd413e1f25bf5c48ff4547470e28effdd4646c2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cfd00de97b591eebbd27bc2c4dd413e1f25bf5c48ff4547470e28effdd4646c2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cfd00de97b591eebbd27bc2c4dd413e1f25bf5c48ff4547470e28effdd4646c2", kill_on_drop: false }`
[INFO] [stdout] cfd00de97b591eebbd27bc2c4dd413e1f25bf5c48ff4547470e28effdd4646c2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 707ae6081df4a57f1eef83e5d5532961065636d14d1a3dbc72b719f416d355e4
[INFO] running `Command { std: "docker" "start" "-a" "707ae6081df4a57f1eef83e5d5532961065636d14d1a3dbc72b719f416d355e4", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.42
[INFO] [stderr]     Checking rand_core v0.2.1
[INFO] [stderr]     Checking rand v0.5.1
[INFO] [stderr]     Checking word_generator v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |         let mut v = vec![$($e),*];
[INFO] [stdout]    |             ----^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] ...
[INFO] [stdout] 72 |     let v = seq![opt!(C), C, V, opt!(C), C, V, opt!(C)]; // generates (C)CV(C)CV(C) words
[INFO] [stdout]    |             ------------------------------------------- in this macro invocation
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `seq` (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: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |         let mut v = vec![$($e),*];
[INFO] [stdout]    |             ----^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] ...
[INFO] [stdout] 72 |     let v = seq![opt!(C), C, V, opt!(C), C, V, opt!(C)]; // generates (C)CV(C)CV(C) words
[INFO] [stdout]    |             ------------------------------------------- in this macro invocation
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `seq` (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] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.70s
[INFO] running `Command { std: "docker" "inspect" "707ae6081df4a57f1eef83e5d5532961065636d14d1a3dbc72b719f416d355e4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "707ae6081df4a57f1eef83e5d5532961065636d14d1a3dbc72b719f416d355e4", kill_on_drop: false }`
[INFO] [stdout] 707ae6081df4a57f1eef83e5d5532961065636d14d1a3dbc72b719f416d355e4