[INFO] cloning repository https://github.com/mingyuan-f/rust_lab
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mingyuan-f/rust_lab" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmingyuan-f%2Frust_lab", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmingyuan-f%2Frust_lab'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cb4d855ce764c1111828decfb10991fe7f93dac9
[INFO] checking mingyuan-f/rust_lab against try#bb9dbf1d07454a99066eabaabd5819851281494b for pr-80920
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmingyuan-f%2Frust_lab" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mingyuan-f/rust_lab on toolchain bb9dbf1d07454a99066eabaabd5819851281494b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+bb9dbf1d07454a99066eabaabd5819851281494b" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mingyuan-f/rust_lab
[INFO] finished tweaking git repo https://github.com/mingyuan-f/rust_lab
[INFO] tweaked toml for git repo https://github.com/mingyuan-f/rust_lab written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/mingyuan-f/rust_lab already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+bb9dbf1d07454a99066eabaabd5819851281494b" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "+bb9dbf1d07454a99066eabaabd5819851281494b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f91af549ee84e01f78e4acbfc60c5d0d408989798988d1abc04c05018c9ca52a
[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" "f91af549ee84e01f78e4acbfc60c5d0d408989798988d1abc04c05018c9ca52a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f91af549ee84e01f78e4acbfc60c5d0d408989798988d1abc04c05018c9ca52a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f91af549ee84e01f78e4acbfc60c5d0d408989798988d1abc04c05018c9ca52a", kill_on_drop: false }`
[INFO] [stdout] f91af549ee84e01f78e4acbfc60c5d0d408989798988d1abc04c05018c9ca52a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "+bb9dbf1d07454a99066eabaabd5819851281494b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 742e4534a7a7ad36bc4dda067cde7c01df51773a6f59689bd778b62e0ae6a45b
[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" "742e4534a7a7ad36bc4dda067cde7c01df51773a6f59689bd778b62e0ae6a45b", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_lab v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `Arc`, `Mutex`, `RwLock`
[INFO] [stdout]  --> examples/thread.rs:3:17
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::sync::{Arc, Mutex, RwLock};
[INFO] [stdout]   |                 ^^^  ^^^^^  ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> examples/thread.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let mut s = S {
[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: field is never read: `ref_value`
[INFO] [stdout]   --> examples/thread.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 |     ref_value: &'v Value,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]  --> examples/reference_rule.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let r1 = &s;
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]  --> examples/reference_rule.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let r2 = &s; // no problem
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r3`
[INFO] [stdout]  --> examples/reference_rule.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let r3 = &mut s; // BIG PROBLEM
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_r3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.44s
[INFO] running `Command { std: "docker" "inspect" "742e4534a7a7ad36bc4dda067cde7c01df51773a6f59689bd778b62e0ae6a45b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "742e4534a7a7ad36bc4dda067cde7c01df51773a6f59689bd778b62e0ae6a45b", kill_on_drop: false }`
[INFO] [stdout] 742e4534a7a7ad36bc4dda067cde7c01df51773a6f59689bd778b62e0ae6a45b