[INFO] cloning repository https://github.com/yangcancai/hello_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/yangcancai/hello_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyangcancai%2Fhello_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyangcancai%2Fhello_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 187f6db12836aeac95be2e46f27fdf4f2b806c13
[INFO] checking yangcancai/hello_rust against master#36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923 for pr-81863
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyangcancai%2Fhello_rust" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/yangcancai/hello_rust on toolchain 36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/yangcancai/hello_rust
[INFO] finished tweaking git repo https://github.com/yangcancai/hello_rust
[INFO] tweaked toml for git repo https://github.com/yangcancai/hello_rust written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/yangcancai/hello_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "fetch" "--locked" "--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-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "rustops/crates-build-env@sha256:ce6408862c0f4858e6cd2b85b2cf085ff7d0d6323904d0a94b71664a228554ab" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 15cfd06fdc46430320c3e7e435f710988dfb954c6b52017cd7ba19af3fb4ce28
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "15cfd06fdc46430320c3e7e435f710988dfb954c6b52017cd7ba19af3fb4ce28", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "15cfd06fdc46430320c3e7e435f710988dfb954c6b52017cd7ba19af3fb4ce28", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "15cfd06fdc46430320c3e7e435f710988dfb954c6b52017cd7ba19af3fb4ce28", kill_on_drop: false }`
[INFO] [stdout] 15cfd06fdc46430320c3e7e435f710988dfb954c6b52017cd7ba19af3fb4ce28
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "rustops/crates-build-env@sha256:ce6408862c0f4858e6cd2b85b2cf085ff7d0d6323904d0a94b71664a228554ab" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 665d9cc4f25bc06d006aa4dc38acdd9ce2750ca60b06d8314b1f1c6b4a4d88c4
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "665d9cc4f25bc06d006aa4dc38acdd9ce2750ca60b06d8314b1f1c6b4a4d88c4", kill_on_drop: false }`
[INFO] [stderr]     Checking rand_core v0.4.2
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]    Compiling libc v0.2.80
[INFO] [stderr]     Checking http_server v0.1.0 (/opt/rustwide/workdir/http_server)
[INFO] [stdout] warning: field is never read: `id`
[INFO] [stdout]   --> http_server/src/lib.rs:25:5
[INFO] [stdout]    |
[INFO] [stdout] 25 |     id: usize,
[INFO] [stdout]    |     ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking rand_jitter v0.1.4
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking guess_game v0.1.0 (/opt/rustwide/workdir/guess_game)
[INFO] [stderr]     Checking hello_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `b`
[INFO] [stdout]    --> src/lib.rs:216:9
[INFO] [stdout]     |
[INFO] [stdout] 216 |         b: &'a P,
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:210:12
[INFO] [stdout]     |
[INFO] [stdout] 210 |     #[warn(dead_code)]
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `b`
[INFO] [stdout]    --> src/lib.rs:216:9
[INFO] [stdout]     |
[INFO] [stdout] 216 |         b: &'a P,
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:210:12
[INFO] [stdout]     |
[INFO] [stdout] 210 |     #[warn(dead_code)]
[INFO] [stdout]     |            ^^^^^^^^^
[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] [stdout] warning: field is never read: `b`
[INFO] [stdout]    --> src/lib.rs:216:9
[INFO] [stdout]     |
[INFO] [stdout] 216 |         b: &'a P,
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:210:12
[INFO] [stdout]     |
[INFO] [stdout] 210 |     #[warn(dead_code)]
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Context`
[INFO] [stdout]    --> src/lib.rs:362:16
[INFO] [stdout]     |
[INFO] [stdout] 362 |     pub struct Context<T: Task> {
[INFO] [stdout]     |                ^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `run`
[INFO] [stdout]    --> src/lib.rs:366:16
[INFO] [stdout]     |
[INFO] [stdout] 366 |         pub fn run(&self) {
[INFO] [stdout]     |                ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `install`
[INFO] [stdout]    --> src/lib.rs:371:16
[INFO] [stdout]     |
[INFO] [stdout] 371 |         pub fn install(&mut self, plug: T) {
[INFO] [stdout]     |                ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `b`
[INFO] [stdout]    --> src/lib.rs:216:9
[INFO] [stdout]     |
[INFO] [stdout] 216 |         b: &'a P,
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:210:12
[INFO] [stdout]     |
[INFO] [stdout] 210 |     #[warn(dead_code)]
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Context`
[INFO] [stdout]    --> src/lib.rs:362:16
[INFO] [stdout]     |
[INFO] [stdout] 362 |     pub struct Context<T: Task> {
[INFO] [stdout]     |                ^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `run`
[INFO] [stdout]    --> src/lib.rs:366:16
[INFO] [stdout]     |
[INFO] [stdout] 366 |         pub fn run(&self) {
[INFO] [stdout]     |                ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `install`
[INFO] [stdout]    --> src/lib.rs:371:16
[INFO] [stdout]     |
[INFO] [stdout] 371 |         pub fn install(&mut self, plug: T) {
[INFO] [stdout]     |                ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.12s
[INFO] running `Command { std: "docker" "inspect" "665d9cc4f25bc06d006aa4dc38acdd9ce2750ca60b06d8314b1f1c6b4a4d88c4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "665d9cc4f25bc06d006aa4dc38acdd9ce2750ca60b06d8314b1f1c6b4a4d88c4", kill_on_drop: false }`
[INFO] [stdout] 665d9cc4f25bc06d006aa4dc38acdd9ce2750ca60b06d8314b1f1c6b4a4d88c4