[INFO] cloning repository https://github.com/25ma/rust_book
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/25ma/rust_book" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F25ma%2Frust_book", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F25ma%2Frust_book'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 394ead8eec2d526c01474e85a7fe7e595b97d712
[INFO] checking 25ma/rust_book against master#04ff05c9c0cfbca33115c5f1b8bb20a66a54b799 for pr-147834
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F25ma%2Frust_book" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/25ma/rust_book
[INFO] finished tweaking git repo https://github.com/25ma/rust_book
[INFO] tweaked toml for git repo https://github.com/25ma/rust_book written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/25ma/rust_book on toolchain 04ff05c9c0cfbca33115c5f1b8bb20a66a54b799
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+04ff05c9c0cfbca33115c5f1b8bb20a66a54b799" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/25ma/rust_book already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+04ff05c9c0cfbca33115c5f1b8bb20a66a54b799" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded wasi v0.10.2+wasi-snapshot-preview1
[INFO] [stderr]   Downloaded rand_hc v0.3.1
[INFO] [stderr]   Downloaded getrandom v0.2.4
[INFO] [stderr]   Downloaded rand v0.8.4
[INFO] [stderr]   Downloaded libc v0.2.117
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+04ff05c9c0cfbca33115c5f1b8bb20a66a54b799" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 627b2842779222bef74f42e79f82e920b3735ce35d4d2ea40ccc5f9773bb8db2
[INFO] running `Command { std: "docker" "start" "-a" "627b2842779222bef74f42e79f82e920b3735ce35d4d2ea40ccc5f9773bb8db2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "627b2842779222bef74f42e79f82e920b3735ce35d4d2ea40ccc5f9773bb8db2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "627b2842779222bef74f42e79f82e920b3735ce35d4d2ea40ccc5f9773bb8db2", kill_on_drop: false }`
[INFO] [stdout] 627b2842779222bef74f42e79f82e920b3735ce35d4d2ea40ccc5f9773bb8db2
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+04ff05c9c0cfbca33115c5f1b8bb20a66a54b799" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 618c6d65271f36f4eb1f15ac1cda83ddb48ee40b6c83d255a9fae1a0b73787fd
[INFO] running `Command { std: "docker" "start" "-a" "618c6d65271f36f4eb1f15ac1cda83ddb48ee40b6c83d255a9fae1a0b73787fd", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.117
[INFO] [stderr]     Checking ppv-lite86 v0.2.16
[INFO] [stderr]     Checking getrandom v0.2.4
[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 rust_book v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/03_common_programming_concepts/function.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |         let mut x = 5 + 1;
[INFO] [stdout]    |             ----^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/03_common_programming_concepts/function.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |         let mut x = 5 + 1;
[INFO] [stdout]    |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `active`, `username`, `email`, and `sign_in_count` are never read
[INFO] [stdout]   --> src/05_structs/defining_structs.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     struct User {
[INFO] [stdout]    |            ---- fields in this struct
[INFO] [stdout] 11 |         active: bool,
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout] 12 |         username: String,
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout] 13 |         email: String,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 14 |         sign_in_count: u64,
[INFO] [stdout]    |         ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `User` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/03_common_programming_concepts/function.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |         let mut x = 5 + 1;
[INFO] [stdout]    |             ----^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/03_common_programming_concepts/function.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |         let mut x = 5 + 1;
[INFO] [stdout]    |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `kind` and `address` are never read
[INFO] [stdout]   --> src/06_enums/defining_enum.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     struct IpAddr {
[INFO] [stdout]    |            ------ fields in this struct
[INFO] [stdout] 18 |         kind: IpAddrKind,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 19 |         address: String,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `IpAddr` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.45s
[INFO] running `Command { std: "docker" "inspect" "618c6d65271f36f4eb1f15ac1cda83ddb48ee40b6c83d255a9fae1a0b73787fd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "618c6d65271f36f4eb1f15ac1cda83ddb48ee40b6c83d255a9fae1a0b73787fd", kill_on_drop: false }`
[INFO] [stdout] 618c6d65271f36f4eb1f15ac1cda83ddb48ee40b6c83d255a9fae1a0b73787fd
