[INFO] cloning repository https://github.com/shanelonergan/rust_common_concepts
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/shanelonergan/rust_common_concepts" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshanelonergan%2Frust_common_concepts", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshanelonergan%2Frust_common_concepts'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 559727dd5e9ccc611f9f03ccdab034728e49d1d3
[INFO] checking shanelonergan/rust_common_concepts against master#a609fb45efad59dfd459c76e50899be9f0583b5a for pr-80579
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshanelonergan%2Frust_common_concepts" "/workspace/builds/worker-12/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-12/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/shanelonergan/rust_common_concepts on toolchain a609fb45efad59dfd459c76e50899be9f0583b5a
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/shanelonergan/rust_common_concepts
[INFO] finished tweaking git repo https://github.com/shanelonergan/rust_common_concepts
[INFO] tweaked toml for git repo https://github.com/shanelonergan/rust_common_concepts written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate git repo https://github.com/shanelonergan/rust_common_concepts already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2bba938a738c08ce2316fc9dbdd60717a00ef05ec91b6feeb5cb2c84a875cdeb
[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" "2bba938a738c08ce2316fc9dbdd60717a00ef05ec91b6feeb5cb2c84a875cdeb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2bba938a738c08ce2316fc9dbdd60717a00ef05ec91b6feeb5cb2c84a875cdeb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2bba938a738c08ce2316fc9dbdd60717a00ef05ec91b6feeb5cb2c84a875cdeb", kill_on_drop: false }`
[INFO] [stdout] 2bba938a738c08ce2316fc9dbdd60717a00ef05ec91b6feeb5cb2c84a875cdeb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 01a4690af61eaf59af840d7a704e64a82d9a1867565555610e5db07c2e32609d
[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" "01a4690af61eaf59af840d7a704e64a82d9a1867565555610e5db07c2e32609d", kill_on_drop: false }`
[INFO] [stderr]     Checking variables v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `sum`
[INFO] [stdout]   --> src/main.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let sum = 5 + 10;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_sum`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `difference`
[INFO] [stdout]   --> src/main.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let difference = 95.5 - 4.3;
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_difference`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `product`
[INFO] [stdout]   --> src/main.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let product = 4 * 30;
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_product`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `quotient`
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let quotient = 56.7 / 32.2;
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_quotient`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `remainder`
[INFO] [stdout]   --> src/main.rs:40:9
[INFO] [stdout]    |
[INFO] [stdout] 40 |     let remainder = 43 % 5;
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_remainder`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/main.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |     let t = true;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:44:9
[INFO] [stdout]    |
[INFO] [stdout] 44 |     let f: bool = false; // with explicit type annotation
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/main.rs:47:9
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let c = '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:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let z = 'ℤ';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `heart_eyed_cat`
[INFO] [stdout]   --> src/main.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let heart_eyed_cat = '😻';
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_heart_eyed_cat`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tup`
[INFO] [stdout]   --> src/main.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let tup: (i32, f64, u8) = (500, 6.4, 1);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_tup`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:55:10
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let (x, y, z) = tup; // destructuring
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/main.rs:55:16
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let (x, y, z) = tup; // destructuring
[INFO] [stdout]    |                ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `five_hundred`
[INFO] [stdout]   --> src/main.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let five_hundred = x.0;
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_five_hundred`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six_point_four`
[INFO] [stdout]   --> src/main.rs:61:9
[INFO] [stdout]    |
[INFO] [stdout] 61 |     let six_point_four = x.1;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_six_point_four`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `one`
[INFO] [stdout]   --> src/main.rs:62:9
[INFO] [stdout]    |
[INFO] [stdout] 62 |     let one = x.2;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_one`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `months`
[INFO] [stdout]   --> src/main.rs:66:9
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let months = ["January", "February", "March", "April", "May", "June", "July",
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_months`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/main.rs:69:9
[INFO] [stdout]    |
[INFO] [stdout] 69 |     let a: [i32; 5] = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/main.rs:70:9
[INFO] [stdout]    |
[INFO] [stdout] 70 |     let a = [3; 5]; // same as let a = [3, 3, 3, 3, 3]
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]   --> src/main.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let first = a[0];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `second`
[INFO] [stdout]   --> src/main.rs:74:9
[INFO] [stdout]    |
[INFO] [stdout] 74 |     let second = a[1];
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_second`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 21 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sum`
[INFO] [stdout]   --> src/main.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let sum = 5 + 10;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_sum`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `difference`
[INFO] [stdout]   --> src/main.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let difference = 95.5 - 4.3;
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_difference`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `product`
[INFO] [stdout]   --> src/main.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let product = 4 * 30;
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_product`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `quotient`
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let quotient = 56.7 / 32.2;
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_quotient`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `remainder`
[INFO] [stdout]   --> src/main.rs:40:9
[INFO] [stdout]    |
[INFO] [stdout] 40 |     let remainder = 43 % 5;
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_remainder`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/main.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |     let t = true;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:44:9
[INFO] [stdout]    |
[INFO] [stdout] 44 |     let f: bool = false; // with explicit type annotation
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/main.rs:47:9
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let c = '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:48:9
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let z = 'ℤ';
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `heart_eyed_cat`
[INFO] [stdout]   --> src/main.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let heart_eyed_cat = '😻';
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_heart_eyed_cat`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `tup`
[INFO] [stdout]   --> src/main.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let tup: (i32, f64, u8) = (500, 6.4, 1);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_tup`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:55:10
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let (x, y, z) = tup; // destructuring
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/main.rs:55:16
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let (x, y, z) = tup; // destructuring
[INFO] [stdout]    |                ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `five_hundred`
[INFO] [stdout]   --> src/main.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let five_hundred = x.0;
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_five_hundred`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six_point_four`
[INFO] [stdout]   --> src/main.rs:61:9
[INFO] [stdout]    |
[INFO] [stdout] 61 |     let six_point_four = x.1;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_six_point_four`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `one`
[INFO] [stdout]   --> src/main.rs:62:9
[INFO] [stdout]    |
[INFO] [stdout] 62 |     let one = x.2;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_one`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `months`
[INFO] [stdout]   --> src/main.rs:66:9
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let months = ["January", "February", "March", "April", "May", "June", "July",
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_months`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/main.rs:69:9
[INFO] [stdout]    |
[INFO] [stdout] 69 |     let a: [i32; 5] = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/main.rs:70:9
[INFO] [stdout]    |
[INFO] [stdout] 70 |     let a = [3; 5]; // same as let a = [3, 3, 3, 3, 3]
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]   --> src/main.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let first = a[0];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `second`
[INFO] [stdout]   --> src/main.rs:74:9
[INFO] [stdout]    |
[INFO] [stdout] 74 |     let second = a[1];
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_second`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 21 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.63s
[INFO] running `Command { std: "docker" "inspect" "01a4690af61eaf59af840d7a704e64a82d9a1867565555610e5db07c2e32609d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "01a4690af61eaf59af840d7a704e64a82d9a1867565555610e5db07c2e32609d", kill_on_drop: false }`
[INFO] [stdout] 01a4690af61eaf59af840d7a704e64a82d9a1867565555610e5db07c2e32609d