[INFO] cloning repository https://github.com/rmsthebest/nullable-first-follow
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/rmsthebest/nullable-first-follow" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frmsthebest%2Fnullable-first-follow", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frmsthebest%2Fnullable-first-follow'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] fac3a77c4de1f7e645a1fbdf8369b31179f69de5
[INFO] checking rmsthebest/nullable-first-follow against try#39e1293fce4b650061e85dda88aa428f726a8444 for pr-88041
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frmsthebest%2Fnullable-first-follow" "/workspace/builds/worker-17/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-17/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/rmsthebest/nullable-first-follow on toolchain 39e1293fce4b650061e85dda88aa428f726a8444
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/rmsthebest/nullable-first-follow
[INFO] finished tweaking git repo https://github.com/rmsthebest/nullable-first-follow
[INFO] tweaked toml for git repo https://github.com/rmsthebest/nullable-first-follow written to /workspace/builds/worker-17/source/Cargo.toml
[INFO] crate git repo https://github.com/rmsthebest/nullable-first-follow already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "+39e1293fce4b650061e85dda88aa428f726a8444" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3ff2a032f377d907560167772eced4606623cd793ad2c51726b37a08f778d82e
[INFO] running `Command { std: "docker" "start" "-a" "3ff2a032f377d907560167772eced4606623cd793ad2c51726b37a08f778d82e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3ff2a032f377d907560167772eced4606623cd793ad2c51726b37a08f778d82e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3ff2a032f377d907560167772eced4606623cd793ad2c51726b37a08f778d82e", kill_on_drop: false }`
[INFO] [stdout] 3ff2a032f377d907560167772eced4606623cd793ad2c51726b37a08f778d82e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "+39e1293fce4b650061e85dda88aa428f726a8444" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 09495ae995a44446d822daeef946dfaef7aaae71bca84716b4da24cbd7d3d817
[INFO] running `Command { std: "docker" "start" "-a" "09495ae995a44446d822daeef946dfaef7aaae71bca84716b4da24cbd7d3d817", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking byteorder v1.2.7
[INFO] [stderr]     Checking scopeguard v0.3.3
[INFO] [stderr]     Checking hashbrown v0.1.0
[INFO] [stderr]     Checking nff v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:61:17
[INFO] [stdout]    |
[INFO] [stdout] 61 |             let mut rhs = side.next().expect("Missing right hand side").trim().chars();
[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: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:61:17
[INFO] [stdout]    |
[INFO] [stdout] 61 |             let mut rhs = side.next().expect("Missing right hand side").trim().chars();
[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] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.20s
[INFO] running `Command { std: "docker" "inspect" "09495ae995a44446d822daeef946dfaef7aaae71bca84716b4da24cbd7d3d817", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "09495ae995a44446d822daeef946dfaef7aaae71bca84716b4da24cbd7d3d817", kill_on_drop: false }`
[INFO] [stdout] 09495ae995a44446d822daeef946dfaef7aaae71bca84716b4da24cbd7d3d817