[INFO] cloning 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" "clone" "--bare" "https://github.com/ravendyg/rust-playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fravendyg%2Frust-playground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fravendyg%2Frust-playground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f0fbaf1c751f3fbfd6b05d9779721bfa5fc7f25f
[INFO] checking ravendyg/rust-playground against master#430feb24a46993e5073c1bb1b39da190d83fa2bf for pr-78363
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fravendyg%2Frust-playground" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ravendyg/rust-playground on toolchain 430feb24a46993e5073c1bb1b39da190d83fa2bf
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+430feb24a46993e5073c1bb1b39da190d83fa2bf" "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-4/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" "+430feb24a46993e5073c1bb1b39da190d83fa2bf" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+430feb24a46993e5073c1bb1b39da190d83fa2bf" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8c332ea91471b400e76e4f85a8b4d0e9010fa81eeb31ada0c0112dcdc70066b2
[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" "8c332ea91471b400e76e4f85a8b4d0e9010fa81eeb31ada0c0112dcdc70066b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8c332ea91471b400e76e4f85a8b4d0e9010fa81eeb31ada0c0112dcdc70066b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c332ea91471b400e76e4f85a8b4d0e9010fa81eeb31ada0c0112dcdc70066b2", kill_on_drop: false }`
[INFO] [stdout] 8c332ea91471b400e76e4f85a8b4d0e9010fa81eeb31ada0c0112dcdc70066b2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+430feb24a46993e5073c1bb1b39da190d83fa2bf" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7cdf23de33f6ecb972ce1e2364f6ee26b21ba0d49fb7dd7dfb6495c4e36e935c
[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" "7cdf23de33f6ecb972ce1e2364f6ee26b21ba0d49fb7dd7dfb6495c4e36e935c", 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 2.09s
[INFO] running `Command { std: "docker" "inspect" "7cdf23de33f6ecb972ce1e2364f6ee26b21ba0d49fb7dd7dfb6495c4e36e935c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7cdf23de33f6ecb972ce1e2364f6ee26b21ba0d49fb7dd7dfb6495c4e36e935c", kill_on_drop: false }`
[INFO] [stdout] 7cdf23de33f6ecb972ce1e2364f6ee26b21ba0d49fb7dd7dfb6495c4e36e935c