[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] a34824be98d024c88df276c64dc0d2aeae502301
[INFO] checking yangcancai/hello_rust against try#15a786332e2f0dd343b226ab6bb8ec028a350f73 for pr-81782
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyangcancai%2Fhello_rust" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/yangcancai/hello_rust on toolchain 15a786332e2f0dd343b226ab6bb8ec028a350f73
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+15a786332e2f0dd343b226ab6bb8ec028a350f73" "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-1/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" "+15a786332e2f0dd343b226ab6bb8ec028a350f73" "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-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+15a786332e2f0dd343b226ab6bb8ec028a350f73" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 14ed5e36c56743a70c4a4d213799e07cfbbe054900bd78934171a32b7c3f48e4
[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" "14ed5e36c56743a70c4a4d213799e07cfbbe054900bd78934171a32b7c3f48e4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "14ed5e36c56743a70c4a4d213799e07cfbbe054900bd78934171a32b7c3f48e4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "14ed5e36c56743a70c4a4d213799e07cfbbe054900bd78934171a32b7c3f48e4", kill_on_drop: false }`
[INFO] [stdout] 14ed5e36c56743a70c4a4d213799e07cfbbe054900bd78934171a32b7c3f48e4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+15a786332e2f0dd343b226ab6bb8ec028a350f73" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2f7c1e636a1bffdee9e166f5179a287d810d1738ce087f177e0c1d29110aa04d
[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" "2f7c1e636a1bffdee9e166f5179a287d810d1738ce087f177e0c1d29110aa04d", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.85
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling syn v1.0.60
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling proc-macro-nested v0.1.7
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]     Checking once_cell v1.5.2
[INFO] [stderr]     Checking futures-io v0.3.12
[INFO] [stderr]     Checking pin-project-lite v0.2.4
[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 futures-channel v0.3.12
[INFO] [stderr]     Checking futures-task v0.3.12
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking guess_game v0.1.0 (/opt/rustwide/workdir/guess_game)
[INFO] [stderr]    Compiling futures-macro v0.3.12
[INFO] [stderr]     Checking futures-util v0.3.12
[INFO] [stderr]     Checking futures-executor v0.3.12
[INFO] [stderr]     Checking futures v0.3.12
[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 hello_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `b`
[INFO] [stdout]    --> src/lib.rs:217:9
[INFO] [stdout]     |
[INFO] [stdout] 217 |         b: &'a P,
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:211:12
[INFO] [stdout]     |
[INFO] [stdout] 211 |     #[warn(dead_code)]
[INFO] [stdout]     |            ^^^^^^^^^
[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:217:9
[INFO] [stdout]     |
[INFO] [stdout] 217 |         b: &'a P,
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:211:12
[INFO] [stdout]     |
[INFO] [stdout] 211 |     #[warn(dead_code)]
[INFO] [stdout]     |            ^^^^^^^^^
[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:217:9
[INFO] [stdout]     |
[INFO] [stdout] 217 |         b: &'a P,
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:211:12
[INFO] [stdout]     |
[INFO] [stdout] 211 |     #[warn(dead_code)]
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Context`
[INFO] [stdout]    --> src/lib.rs:363:16
[INFO] [stdout]     |
[INFO] [stdout] 363 |     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:367:16
[INFO] [stdout]     |
[INFO] [stdout] 367 |         pub fn run(&self) {
[INFO] [stdout]     |                ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `install`
[INFO] [stdout]    --> src/lib.rs:372:16
[INFO] [stdout]     |
[INFO] [stdout] 372 |         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:217:9
[INFO] [stdout]     |
[INFO] [stdout] 217 |         b: &'a P,
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:211:12
[INFO] [stdout]     |
[INFO] [stdout] 211 |     #[warn(dead_code)]
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Context`
[INFO] [stdout]    --> src/lib.rs:363:16
[INFO] [stdout]     |
[INFO] [stdout] 363 |     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:367:16
[INFO] [stdout]     |
[INFO] [stdout] 367 |         pub fn run(&self) {
[INFO] [stdout]     |                ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `install`
[INFO] [stdout]    --> src/lib.rs:372:16
[INFO] [stdout]     |
[INFO] [stdout] 372 |         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 38.91s
[INFO] running `Command { std: "docker" "inspect" "2f7c1e636a1bffdee9e166f5179a287d810d1738ce087f177e0c1d29110aa04d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2f7c1e636a1bffdee9e166f5179a287d810d1738ce087f177e0c1d29110aa04d", kill_on_drop: false }`
[INFO] [stdout] 2f7c1e636a1bffdee9e166f5179a287d810d1738ce087f177e0c1d29110aa04d