[INFO] cloning repository https://github.com/Alvynskio/rust_book_projects
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Alvynskio/rust_book_projects" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAlvynskio%2Frust_book_projects", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAlvynskio%2Frust_book_projects'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0271a7f2692e09d0e86549849fc1cdc0cd314cb2
[INFO] checking Alvynskio/rust_book_projects against try#cac44d9528e3bbbdaa1537d187bd489ccc5de18c for pr-91141
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAlvynskio%2Frust_book_projects" "/workspace/builds/worker-18/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-18/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Alvynskio/rust_book_projects 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 git repo https://github.com/Alvynskio/rust_book_projects
[INFO] finished tweaking git repo https://github.com/Alvynskio/rust_book_projects
[INFO] tweaked toml for git repo https://github.com/Alvynskio/rust_book_projects written to /workspace/builds/worker-18/source/Cargo.toml
[INFO] crate git repo https://github.com/Alvynskio/rust_book_projects already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "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-18/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/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] 382db5c07bfcd5f31839271846c79377ae1700345bb7eac988934d45146508e4
[INFO] running `Command { std: "docker" "start" "-a" "382db5c07bfcd5f31839271846c79377ae1700345bb7eac988934d45146508e4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "382db5c07bfcd5f31839271846c79377ae1700345bb7eac988934d45146508e4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "382db5c07bfcd5f31839271846c79377ae1700345bb7eac988934d45146508e4", kill_on_drop: false }`
[INFO] [stdout] 382db5c07bfcd5f31839271846c79377ae1700345bb7eac988934d45146508e4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/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] a46b533aecc36fb689e988bd0d9a1d7b3e8e40d61df6e12c9a179487f2c51e09
[INFO] running `Command { std: "docker" "start" "-a" "a46b533aecc36fb689e988bd0d9a1d7b3e8e40d61df6e12c9a179487f2c51e09", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.103
[INFO] [stderr]     Checking getrandom v0.2.3
[INFO] [stderr]     Checking rand_core v0.6.3
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.4
[INFO] [stderr]     Checking book_projects v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/slice.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut s = String::from("hello world");
[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/slice.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut s = String::from("hello world");
[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 14.42s
[INFO] running `Command { std: "docker" "inspect" "a46b533aecc36fb689e988bd0d9a1d7b3e8e40d61df6e12c9a179487f2c51e09", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a46b533aecc36fb689e988bd0d9a1d7b3e8e40d61df6e12c9a179487f2c51e09", kill_on_drop: false }`
[INFO] [stdout] a46b533aecc36fb689e988bd0d9a1d7b3e8e40d61df6e12c9a179487f2c51e09