[INFO] cloning repository https://github.com/fredhsu/rustbook-exercises
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/fredhsu/rustbook-exercises" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffredhsu%2Frustbook-exercises", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffredhsu%2Frustbook-exercises'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d479ef03ca7e702dff0c3e8fa72ccf9eee1c83be
[INFO] checking fredhsu/rustbook-exercises against master#8f21a5c92ea55c348c275a1bc4fedbdf181e0d64 for pr-143011
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffredhsu%2Frustbook-exercises" "/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/fredhsu/rustbook-exercises
[INFO] finished tweaking git repo https://github.com/fredhsu/rustbook-exercises
[INFO] tweaked toml for git repo https://github.com/fredhsu/rustbook-exercises written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/fredhsu/rustbook-exercises on toolchain 8f21a5c92ea55c348c275a1bc4fedbdf181e0d64
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8f21a5c92ea55c348c275a1bc4fedbdf181e0d64" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/fredhsu/rustbook-exercises 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" "+8f21a5c92ea55c348c275a1bc4fedbdf181e0d64" "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-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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+8f21a5c92ea55c348c275a1bc4fedbdf181e0d64" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ff5b1041a1747e0353ed14e4f19a0a4a09b121a1550dd19e5137bdde534dfbef
[INFO] running `Command { std: "docker" "start" "-a" "ff5b1041a1747e0353ed14e4f19a0a4a09b121a1550dd19e5137bdde534dfbef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ff5b1041a1747e0353ed14e4f19a0a4a09b121a1550dd19e5137bdde534dfbef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ff5b1041a1747e0353ed14e4f19a0a4a09b121a1550dd19e5137bdde534dfbef", kill_on_drop: false }`
[INFO] [stdout] ff5b1041a1747e0353ed14e4f19a0a4a09b121a1550dd19e5137bdde534dfbef
[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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+8f21a5c92ea55c348c275a1bc4fedbdf181e0d64" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9796c405b555fece743b4ce081c23498ebeec40ba20dc9e6f11d7f625f9557bb
[INFO] running `Command { std: "docker" "start" "-a" "9796c405b555fece743b4ce081c23498ebeec40ba20dc9e6f11d7f625f9557bb", kill_on_drop: false }`
[INFO] [stderr]     Checking rustbook-exercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:98:9
[INFO] [stdout]    |
[INFO] [stdout] 98 |     let i = ImportantExcerpt {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:98:9
[INFO] [stdout]    |
[INFO] [stdout] 98 |     let i = ImportantExcerpt {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `part` is never read
[INFO] [stdout]   --> src/main.rs:41:5
[INFO] [stdout]    |
[INFO] [stdout] 40 | struct ImportantExcerpt<'a> {
[INFO] [stdout]    |        ---------------- field in this struct
[INFO] [stdout] 41 |     part: &'a str,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `level` is never used
[INFO] [stdout]   --> src/main.rs:44:8
[INFO] [stdout]    |
[INFO] [stdout] 43 | impl<'a> ImportantExcerpt<'a> {
[INFO] [stdout]    | ----------------------------- method in this implementation
[INFO] [stdout] 44 |     fn level(&self) -> i32 {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `part` is never read
[INFO] [stdout]   --> src/main.rs:41:5
[INFO] [stdout]    |
[INFO] [stdout] 40 | struct ImportantExcerpt<'a> {
[INFO] [stdout]    |        ---------------- field in this struct
[INFO] [stdout] 41 |     part: &'a str,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `level` is never used
[INFO] [stdout]   --> src/main.rs:44:8
[INFO] [stdout]    |
[INFO] [stdout] 43 | impl<'a> ImportantExcerpt<'a> {
[INFO] [stdout]    | ----------------------------- method in this implementation
[INFO] [stdout] 44 |     fn level(&self) -> i32 {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.25s
[INFO] running `Command { std: "docker" "inspect" "9796c405b555fece743b4ce081c23498ebeec40ba20dc9e6f11d7f625f9557bb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9796c405b555fece743b4ce081c23498ebeec40ba20dc9e6f11d7f625f9557bb", kill_on_drop: false }`
[INFO] [stdout] 9796c405b555fece743b4ce081c23498ebeec40ba20dc9e6f11d7f625f9557bb