[INFO] updating cached repository https://github.com/ravendyg/rust-playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f0fbaf1c751f3fbfd6b05d9779721bfa5fc7f25f
[INFO] checking ravendyg/rust-playground against master#1557fb031b272b4c5bfcc7de5df7eddc7b36a584 for pr-73166
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fravendyg%2Frust-playground" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ravendyg/rust-playground on toolchain 1557fb031b272b4c5bfcc7de5df7eddc7b36a584
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1557fb031b272b4c5bfcc7de5df7eddc7b36a584" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ravendyg/rust-playground
[INFO] finished tweaking git repo https://github.com/ravendyg/rust-playground
[INFO] tweaked toml for git repo https://github.com/ravendyg/rust-playground written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/ravendyg/rust-playground already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1557fb031b272b4c5bfcc7de5df7eddc7b36a584" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1557fb031b272b4c5bfcc7de5df7eddc7b36a584" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] c8e0d1b9df88bb9583fb16d01492db040e7acfc780be01470467ee349cab3ac7
[INFO] running `Command { std: "docker" "start" "-a" "c8e0d1b9df88bb9583fb16d01492db040e7acfc780be01470467ee349cab3ac7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c8e0d1b9df88bb9583fb16d01492db040e7acfc780be01470467ee349cab3ac7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c8e0d1b9df88bb9583fb16d01492db040e7acfc780be01470467ee349cab3ac7", kill_on_drop: false }`
[INFO] [stdout] c8e0d1b9df88bb9583fb16d01492db040e7acfc780be01470467ee349cab3ac7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1557fb031b272b4c5bfcc7de5df7eddc7b36a584" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5260d332e9777cfb1fc75de15d3d009e7b03b976ca5130e01006f4c39743f267
[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" "5260d332e9777cfb1fc75de15d3d009e7b03b976ca5130e01006f4c39743f267", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.18
[INFO] [stderr]     Checking rand v0.3.15
[INFO] [stderr]     Checking guessing v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:60:7
[INFO] [stdout]    |
[INFO] [stdout] 60 |   let x: Option<i32> = Option::Some(5);
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `q`
[INFO] [stdout]   --> src/main.rs:62:7
[INFO] [stdout]    |
[INFO] [stdout] 62 |   let q: Option<f64> = Option::Some(5f64);
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_q`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/main.rs:71:7
[INFO] [stdout]    |
[INFO] [stdout] 71 |   let b = 10;
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `None`
[INFO] [stdout]   --> src/main.rs:49:3
[INFO] [stdout]    |
[INFO] [stdout] 49 |   None
[INFO] [stdout]    |   ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Result`
[INFO] [stdout]   --> src/main.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 | enum Result<T, E> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:60:7
[INFO] [stdout]    |
[INFO] [stdout] 60 |   let x: Option<i32> = Option::Some(5);
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `q`
[INFO] [stdout]   --> src/main.rs:62:7
[INFO] [stdout]    |
[INFO] [stdout] 62 |   let q: Option<f64> = Option::Some(5f64);
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_q`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/main.rs:71:7
[INFO] [stdout]    |
[INFO] [stdout] 71 |   let b = 10;
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `None`
[INFO] [stdout]   --> src/main.rs:49:3
[INFO] [stdout]    |
[INFO] [stdout] 49 |   None
[INFO] [stdout]    |   ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Result`
[INFO] [stdout]   --> src/main.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 | enum Result<T, E> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.95s
[INFO] running `Command { std: "docker" "inspect" "5260d332e9777cfb1fc75de15d3d009e7b03b976ca5130e01006f4c39743f267", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5260d332e9777cfb1fc75de15d3d009e7b03b976ca5130e01006f4c39743f267", kill_on_drop: false }`
[INFO] [stdout] 5260d332e9777cfb1fc75de15d3d009e7b03b976ca5130e01006f4c39743f267