[INFO] cloning repository https://github.com/matt-porter/synacor-challenge
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/matt-porter/synacor-challenge" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmatt-porter%2Fsynacor-challenge", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmatt-porter%2Fsynacor-challenge'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8806e74f13ee2433915153a09385a69fe58b1ed8
[INFO] testing matt-porter/synacor-challenge against beta-2026-04-21 for beta-1.96-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmatt-porter%2Fsynacor-challenge" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/matt-porter/synacor-challenge
[INFO] finished tweaking git repo https://github.com/matt-porter/synacor-challenge
[INFO] tweaked toml for git repo https://github.com/matt-porter/synacor-challenge written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/matt-porter/synacor-challenge on toolchain beta-2026-04-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/matt-porter/synacor-challenge already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 00884345de906b0fd2fceb943ac68aabd794bf3831c961e4ad755bc60aee5674
[INFO] running `Command { std: "docker" "start" "-a" "00884345de906b0fd2fceb943ac68aabd794bf3831c961e4ad755bc60aee5674", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "00884345de906b0fd2fceb943ac68aabd794bf3831c961e4ad755bc60aee5674", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "00884345de906b0fd2fceb943ac68aabd794bf3831c961e4ad755bc60aee5674", kill_on_drop: false }`
[INFO] [stdout] 00884345de906b0fd2fceb943ac68aabd794bf3831c961e4ad755bc60aee5674
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 67f98b260c01f83d97b1e02336df12de28f11342995296470dd6d6455b3255af
[INFO] running `Command { std: "docker" "start" "-a" "67f98b260c01f83d97b1e02336df12de28f11342995296470dd6d6455b3255af", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling quick-error v1.2.2
[INFO] [stderr]    Compiling regex-syntax v0.6.12
[INFO] [stderr]    Compiling termcolor v1.0.5
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stderr]    Compiling humantime v1.3.0
[INFO] [stderr]    Compiling aho-corasick v0.7.6
[INFO] [stderr]    Compiling atty v0.2.13
[INFO] [stderr]    Compiling regex v1.3.1
[INFO] [stderr]    Compiling env_logger v0.7.0
[INFO] [stderr]    Compiling synacor v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::io::prelude::*`
[INFO] [stdout]    --> src/main.rs:372:5
[INFO] [stdout]     |
[INFO] [stdout] 372 | use std::io::prelude::*;
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]    --> src/main.rs:330:9
[INFO] [stdout]     |
[INFO] [stdout] 329 |         std::process::exit(0);
[INFO] [stdout]     |         --------------------- any code following this expression is unreachable
[INFO] [stdout] 330 |         0
[INFO] [stdout]     |         ^ unreachable expression
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `system`
[INFO] [stdout]   --> src/main.rs:97:14
[INFO] [stdout]    |
[INFO] [stdout] 97 | fn op_0_halt(system: &mut System) -> (){
[INFO] [stdout]    |              ^^^^^^ help: if this is intentional, prefix it with an underscore: `_system`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:168:9
[INFO] [stdout]     |
[INFO] [stdout] 168 |     let mut idx = idx + 1;
[INFO] [stdout]     |         ----^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:321:9
[INFO] [stdout]     |
[INFO] [stdout] 321 |     let mut idx = idx + 1;
[INFO] [stdout]     |         ----^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `idx`
[INFO] [stdout]    --> src/main.rs:325:35
[INFO] [stdout]     |
[INFO] [stdout] 325 | fn op_18_ret(system: &mut System, idx: usize) -> usize {
[INFO] [stdout]     |                                   ^^^ help: if this is intentional, prefix it with an underscore: `_idx`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `stdin`
[INFO] [stdout]    --> src/main.rs:354:9
[INFO] [stdout]     |
[INFO] [stdout] 354 |     let stdin = io::stdin().read_exact(&mut buffer);
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_stdin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `system`
[INFO] [stdout]    --> src/main.rs:362:15
[INFO] [stdout]     |
[INFO] [stdout] 362 | fn op_21_noop(system: &mut System, idx: usize) -> usize {
[INFO] [stdout]     |               ^^^^^^ help: if this is intentional, prefix it with an underscore: `_system`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:380:9
[INFO] [stdout]     |
[INFO] [stdout] 380 |     let mut iter = buffer.chunks(2);
[INFO] [stdout]     |         ----^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v5`
[INFO] [stdout]    --> src/main.rs:401:9
[INFO] [stdout]     |
[INFO] [stdout] 401 |     let v5 = v3 + v4;
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_v5`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Value` is never used
[INFO] [stdout]    --> src/main.rs:366:6
[INFO] [stdout]     |
[INFO] [stdout] 366 | enum Value {
[INFO] [stdout]     |      ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 11.05s
[INFO] running `Command { std: "docker" "inspect" "67f98b260c01f83d97b1e02336df12de28f11342995296470dd6d6455b3255af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "67f98b260c01f83d97b1e02336df12de28f11342995296470dd6d6455b3255af", kill_on_drop: false }`
[INFO] [stdout] 67f98b260c01f83d97b1e02336df12de28f11342995296470dd6d6455b3255af
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b230f3d3be0ba38a9161441f4c2d856c154773489b735523670fd1c5738a1f58
[INFO] running `Command { std: "docker" "start" "-a" "b230f3d3be0ba38a9161441f4c2d856c154773489b735523670fd1c5738a1f58", kill_on_drop: false }`
[INFO] [stderr]    Compiling synacor v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::io::prelude::*`
[INFO] [stdout]    --> src/main.rs:372:5
[INFO] [stdout]     |
[INFO] [stdout] 372 | use std::io::prelude::*;
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]    --> src/main.rs:330:9
[INFO] [stdout]     |
[INFO] [stdout] 329 |         std::process::exit(0);
[INFO] [stdout]     |         --------------------- any code following this expression is unreachable
[INFO] [stdout] 330 |         0
[INFO] [stdout]     |         ^ unreachable expression
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `system`
[INFO] [stdout]   --> src/main.rs:97:14
[INFO] [stdout]    |
[INFO] [stdout] 97 | fn op_0_halt(system: &mut System) -> (){
[INFO] [stdout]    |              ^^^^^^ help: if this is intentional, prefix it with an underscore: `_system`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:168:9
[INFO] [stdout]     |
[INFO] [stdout] 168 |     let mut idx = idx + 1;
[INFO] [stdout]     |         ----^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:321:9
[INFO] [stdout]     |
[INFO] [stdout] 321 |     let mut idx = idx + 1;
[INFO] [stdout]     |         ----^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `idx`
[INFO] [stdout]    --> src/main.rs:325:35
[INFO] [stdout]     |
[INFO] [stdout] 325 | fn op_18_ret(system: &mut System, idx: usize) -> usize {
[INFO] [stdout]     |                                   ^^^ help: if this is intentional, prefix it with an underscore: `_idx`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `stdin`
[INFO] [stdout]    --> src/main.rs:354:9
[INFO] [stdout]     |
[INFO] [stdout] 354 |     let stdin = io::stdin().read_exact(&mut buffer);
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_stdin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `system`
[INFO] [stdout]    --> src/main.rs:362:15
[INFO] [stdout]     |
[INFO] [stdout] 362 | fn op_21_noop(system: &mut System, idx: usize) -> usize {
[INFO] [stdout]     |               ^^^^^^ help: if this is intentional, prefix it with an underscore: `_system`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:380:9
[INFO] [stdout]     |
[INFO] [stdout] 380 |     let mut iter = buffer.chunks(2);
[INFO] [stdout]     |         ----^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v5`
[INFO] [stdout]    --> src/main.rs:401:9
[INFO] [stdout]     |
[INFO] [stdout] 401 |     let v5 = v3 + v4;
[INFO] [stdout]     |         ^^ help: if this is intentional, prefix it with an underscore: `_v5`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Value` is never used
[INFO] [stdout]    --> src/main.rs:366:6
[INFO] [stdout]     |
[INFO] [stdout] 366 | enum Value {
[INFO] [stdout]     |      ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.56s
[INFO] running `Command { std: "docker" "inspect" "b230f3d3be0ba38a9161441f4c2d856c154773489b735523670fd1c5738a1f58", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b230f3d3be0ba38a9161441f4c2d856c154773489b735523670fd1c5738a1f58", kill_on_drop: false }`
[INFO] [stdout] b230f3d3be0ba38a9161441f4c2d856c154773489b735523670fd1c5738a1f58
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 35fa9262199bb97558ad75f96b23b8eba75f9fcb28835c3117d0f5e00fd5943d
[INFO] running `Command { std: "docker" "start" "-a" "35fa9262199bb97558ad75f96b23b8eba75f9fcb28835c3117d0f5e00fd5943d", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `std::io::prelude::*`
[INFO] [stderr]    --> src/main.rs:372:5
[INFO] [stderr]     |
[INFO] [stderr] 372 | use std::io::prelude::*;
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unreachable expression
[INFO] [stderr]    --> src/main.rs:330:9
[INFO] [stderr]     |
[INFO] [stderr] 329 |         std::process::exit(0);
[INFO] [stderr]     |         --------------------- any code following this expression is unreachable
[INFO] [stderr] 330 |         0
[INFO] [stderr]     |         ^ unreachable expression
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unreachable_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `system`
[INFO] [stderr]   --> src/main.rs:97:14
[INFO] [stderr]    |
[INFO] [stderr] 97 | fn op_0_halt(system: &mut System) -> (){
[INFO] [stderr]    |              ^^^^^^ help: if this is intentional, prefix it with an underscore: `_system`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:168:9
[INFO] [stderr]     |
[INFO] [stderr] 168 |     let mut idx = idx + 1;
[INFO] [stderr]     |         ----^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:321:9
[INFO] [stderr]     |
[INFO] [stderr] 321 |     let mut idx = idx + 1;
[INFO] [stderr]     |         ----^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `idx`
[INFO] [stderr]    --> src/main.rs:325:35
[INFO] [stderr]     |
[INFO] [stderr] 325 | fn op_18_ret(system: &mut System, idx: usize) -> usize {
[INFO] [stderr]     |                                   ^^^ help: if this is intentional, prefix it with an underscore: `_idx`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `stdin`
[INFO] [stderr]    --> src/main.rs:354:9
[INFO] [stderr]     |
[INFO] [stderr] 354 |     let stdin = io::stdin().read_exact(&mut buffer);
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_stdin`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `system`
[INFO] [stderr]    --> src/main.rs:362:15
[INFO] [stderr]     |
[INFO] [stderr] 362 | fn op_21_noop(system: &mut System, idx: usize) -> usize {
[INFO] [stderr]     |               ^^^^^^ help: if this is intentional, prefix it with an underscore: `_system`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:380:9
[INFO] [stderr]     |
[INFO] [stderr] 380 |     let mut iter = buffer.chunks(2);
[INFO] [stderr]     |         ----^^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `v5`
[INFO] [stderr]    --> src/main.rs:401:9
[INFO] [stderr]     |
[INFO] [stderr] 401 |     let v5 = v3 + v4;
[INFO] [stderr]     |         ^^ help: if this is intentional, prefix it with an underscore: `_v5`
[INFO] [stderr] 
[INFO] [stderr] warning: enum `Value` is never used
[INFO] [stderr]    --> src/main.rs:366:6
[INFO] [stderr]     |
[INFO] [stderr] 366 | enum Value {
[INFO] [stderr]     |      ^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `synacor` (bin "synacor" test) generated 11 warnings (run `cargo fix --bin "synacor" -p synacor --tests` to apply 9 suggestions)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.06s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/synacor-d744a43790a5dcb4)
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] running `Command { std: "docker" "inspect" "35fa9262199bb97558ad75f96b23b8eba75f9fcb28835c3117d0f5e00fd5943d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "35fa9262199bb97558ad75f96b23b8eba75f9fcb28835c3117d0f5e00fd5943d", kill_on_drop: false }`
[INFO] [stdout] 35fa9262199bb97558ad75f96b23b8eba75f9fcb28835c3117d0f5e00fd5943d
