[INFO] cloning repository https://github.com/Cancain/rust_new_tutorial
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Cancain/rust_new_tutorial" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCancain%2Frust_new_tutorial", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCancain%2Frust_new_tutorial'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] eef2526864c89f77392a7e1cf924fe946ddc5723
[INFO] testing Cancain/rust_new_tutorial against try#722e1797249a965b6335aebd65d777f917e498f1 for pr-91031
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCancain%2Frust_new_tutorial" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Cancain/rust_new_tutorial on toolchain 722e1797249a965b6335aebd65d777f917e498f1
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Cancain/rust_new_tutorial
[INFO] finished tweaking git repo https://github.com/Cancain/rust_new_tutorial
[INFO] tweaked toml for git repo https://github.com/Cancain/rust_new_tutorial written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/Cancain/rust_new_tutorial already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 77c1af505d6d41fb9a9336557846cb3a063e8f7eacd43d31b695d46f92cdd8b2
[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" "77c1af505d6d41fb9a9336557846cb3a063e8f7eacd43d31b695d46f92cdd8b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "77c1af505d6d41fb9a9336557846cb3a063e8f7eacd43d31b695d46f92cdd8b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "77c1af505d6d41fb9a9336557846cb3a063e8f7eacd43d31b695d46f92cdd8b2", kill_on_drop: false }`
[INFO] [stdout] 77c1af505d6d41fb9a9336557846cb3a063e8f7eacd43d31b695d46f92cdd8b2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 527ee931c692d5dd91ea6250dbe3b23a80b03ccc80380228ba17d187b41f3870
[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" "527ee931c692d5dd91ea6250dbe3b23a80b03ccc80380228ba17d187b41f3870", kill_on_drop: false }`
[INFO] [stderr]    Compiling play_ground v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]  --> src/main.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let a = 1 + 20;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/main.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s = 30 - 20;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `m`
[INFO] [stdout]  --> src/main.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let m = 5 * 10;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_m`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `d`
[INFO] [stdout]   --> src/main.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let d = 4/6; 
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_d`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r`
[INFO] [stdout]   --> src/main.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let r = 49 % 2;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_r`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/main.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let c = 'c';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/main.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let c: char = 'z';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/main.rs:19:10
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let (z, y, x) = t;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/main.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let (z, y, x) = t;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:19:16
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let (z, y, x) = t;
[INFO] [stdout]    |                ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:20:17
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let (_, _ , x) = t;
[INFO] [stdout]    |                 ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ab1`
[INFO] [stdout]   --> src/main.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let ab1 = ab[0];
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_ab1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.80s
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "527ee931c692d5dd91ea6250dbe3b23a80b03ccc80380228ba17d187b41f3870", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "527ee931c692d5dd91ea6250dbe3b23a80b03ccc80380228ba17d187b41f3870", kill_on_drop: false }`
[INFO] [stdout] 527ee931c692d5dd91ea6250dbe3b23a80b03ccc80380228ba17d187b41f3870
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2cb155d8a22ec9d69debb54818265983032a2212a2462c01da998140e6f47613
[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" "2cb155d8a22ec9d69debb54818265983032a2212a2462c01da998140e6f47613", kill_on_drop: false }`
[INFO] [stderr]    Compiling play_ground v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]  --> src/main.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let a = 1 + 20;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/main.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s = 30 - 20;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `m`
[INFO] [stdout]  --> src/main.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let m = 5 * 10;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_m`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `d`
[INFO] [stdout]   --> src/main.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let d = 4/6; 
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_d`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r`
[INFO] [stdout]   --> src/main.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let r = 49 % 2;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_r`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/main.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let c = 'c';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/main.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let c: char = 'z';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/main.rs:19:10
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let (z, y, x) = t;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/main.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let (z, y, x) = t;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:19:16
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let (z, y, x) = t;
[INFO] [stdout]    |                ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:20:17
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let (_, _ , x) = t;
[INFO] [stdout]    |                 ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ab1`
[INFO] [stdout]   --> src/main.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let ab1 = ab[0];
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_ab1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.86s
[INFO] running `Command { std: "docker" "inspect" "2cb155d8a22ec9d69debb54818265983032a2212a2462c01da998140e6f47613", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2cb155d8a22ec9d69debb54818265983032a2212a2462c01da998140e6f47613", kill_on_drop: false }`
[INFO] [stdout] 2cb155d8a22ec9d69debb54818265983032a2212a2462c01da998140e6f47613
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "test" "--frozen", 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] 5a4800998e9148d38e77b2b2692ebe2d56c93bf3e6fc60962251df4974df817f
[INFO] running `Command { std: "docker" "start" "-a" "5a4800998e9148d38e77b2b2692ebe2d56c93bf3e6fc60962251df4974df817f", kill_on_drop: false }`
[INFO] [stdout] 
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stdout] running 0 tests
[INFO] [stderr]  --> src/main.rs:6:9
[INFO] [stdout] 
[INFO] [stderr]   |
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stderr] 6 |     let a = 1 + 20;
[INFO] [stdout] 
[INFO] [stderr]   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s`
[INFO] [stderr]  --> src/main.rs:8:9
[INFO] [stderr]   |
[INFO] [stderr] 8 |     let s = 30 - 20;
[INFO] [stderr]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `m`
[INFO] [stderr]  --> src/main.rs:9:9
[INFO] [stderr]   |
[INFO] [stderr] 9 |     let m = 5 * 10;
[INFO] [stderr]   |         ^ help: if this is intentional, prefix it with an underscore: `_m`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `d`
[INFO] [stderr]   --> src/main.rs:10:9
[INFO] [stderr]    |
[INFO] [stderr] 10 |     let d = 4/6; 
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_d`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `r`
[INFO] [stderr]   --> src/main.rs:11:9
[INFO] [stderr]    |
[INFO] [stderr] 11 |     let r = 49 % 2;
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_r`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `c`
[INFO] [stderr]   --> src/main.rs:14:9
[INFO] [stderr]    |
[INFO] [stderr] 14 |     let c = 'c';
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `c`
[INFO] [stderr]   --> src/main.rs:15:9
[INFO] [stderr]    |
[INFO] [stderr] 15 |     let c: char = 'z';
[INFO] [stderr]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `z`
[INFO] [stderr]   --> src/main.rs:19:10
[INFO] [stderr]    |
[INFO] [stderr] 19 |     let (z, y, x) = t;
[INFO] [stderr]    |          ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/main.rs:19:13
[INFO] [stderr]    |
[INFO] [stderr] 19 |     let (z, y, x) = t;
[INFO] [stderr]    |             ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:19:16
[INFO] [stderr]    |
[INFO] [stderr] 19 |     let (z, y, x) = t;
[INFO] [stderr]    |                ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:20:17
[INFO] [stderr]    |
[INFO] [stderr] 20 |     let (_, _ , x) = t;
[INFO] [stderr]    |                 ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `ab1`
[INFO] [stderr]   --> src/main.rs:24:9
[INFO] [stderr]    |
[INFO] [stderr] 24 |     let ab1 = ab[0];
[INFO] [stderr]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_ab1`
[INFO] [stderr] 
[INFO] [stderr] warning: `play_ground` (bin "play_ground" test) generated 12 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/play_ground-5b9cf8412e9841ff)
[INFO] running `Command { std: "docker" "inspect" "5a4800998e9148d38e77b2b2692ebe2d56c93bf3e6fc60962251df4974df817f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5a4800998e9148d38e77b2b2692ebe2d56c93bf3e6fc60962251df4974df817f", kill_on_drop: false }`
[INFO] [stdout] 5a4800998e9148d38e77b2b2692ebe2d56c93bf3e6fc60962251df4974df817f