[INFO] fetching crate soku 0.1.1...
[INFO] testing soku-0.1.1 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate soku 0.1.1 into /workspace/builds/worker-0-tc2/source
[INFO] started tweaking crates.io crate soku 0.1.1
[INFO] finished tweaking crates.io crate soku 0.1.1
[INFO] tweaked toml for crates.io crate soku 0.1.1 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate soku 0.1.1 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 crates.io crate soku 0.1.1 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-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 85bf58f6a9f4ee882737c12d0fe44943f00de517a5350b339ad723cf14d81cde
[INFO] running `Command { std: "docker" "start" "-a" "85bf58f6a9f4ee882737c12d0fe44943f00de517a5350b339ad723cf14d81cde", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "85bf58f6a9f4ee882737c12d0fe44943f00de517a5350b339ad723cf14d81cde", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "85bf58f6a9f4ee882737c12d0fe44943f00de517a5350b339ad723cf14d81cde", kill_on_drop: false }`
[INFO] [stdout] 85bf58f6a9f4ee882737c12d0fe44943f00de517a5350b339ad723cf14d81cde
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] a1a08ddef0939f9daeee629d358a0c3ffcc2faca075e14d2c8b0351938ed0937
[INFO] running `Command { std: "docker" "start" "-a" "a1a08ddef0939f9daeee629d358a0c3ffcc2faca075e14d2c8b0351938ed0937", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.53
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling libc v0.2.140
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling thiserror v1.0.40
[INFO] [stderr]    Compiling syn v2.0.8
[INFO] [stderr]    Compiling getrandom v0.2.8
[INFO] [stderr]    Compiling rand_core v0.6.4
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.5
[INFO] [stderr]    Compiling thiserror-impl v1.0.40
[INFO] [stderr]    Compiling derive_more v0.99.17
[INFO] [stderr]    Compiling soku v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/sudoku.rs:645:5
[INFO] [stdout]     |
[INFO] [stdout] 645 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, foreign functions, functions, inherent methods, provided trait methods, required trait methods, and traits
[INFO] [stdout]     = note: `#[warn(unused_attributes)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/sudoku.rs:142:13
[INFO] [stdout]     |
[INFO] [stdout] 142 |         let mut cell = self.cell_mut(i.into_index())?;
[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/sudoku.rs:153:13
[INFO] [stdout]     |
[INFO] [stdout] 153 |         let mut cell = self.cell_mut(i.into_index())?;
[INFO] [stdout]     |             ----^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 10.44s
[INFO] running `Command { std: "docker" "inspect" "a1a08ddef0939f9daeee629d358a0c3ffcc2faca075e14d2c8b0351938ed0937", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a1a08ddef0939f9daeee629d358a0c3ffcc2faca075e14d2c8b0351938ed0937", kill_on_drop: false }`
[INFO] [stdout] a1a08ddef0939f9daeee629d358a0c3ffcc2faca075e14d2c8b0351938ed0937
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] c5774077820073dc13ef0f8d4360de1e0a41279c28edadac4c40249e096fea74
[INFO] running `Command { std: "docker" "start" "-a" "c5774077820073dc13ef0f8d4360de1e0a41279c28edadac4c40249e096fea74", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.140
[INFO] [stderr]    Compiling futures-core v0.3.27
[INFO] [stderr]    Compiling futures-task v0.3.27
[INFO] [stderr]    Compiling futures-channel v0.3.27
[INFO] [stderr]    Compiling futures-util v0.3.27
[INFO] [stderr]    Compiling futures-sink v0.3.27
[INFO] [stderr]    Compiling slab v0.4.8
[INFO] [stderr]    Compiling futures-io v0.3.27
[INFO] [stderr]    Compiling tokio v1.26.0
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling getrandom v0.2.8
[INFO] [stderr]    Compiling num_cpus v1.15.0
[INFO] [stderr]    Compiling rand_core v0.6.4
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.5
[INFO] [stderr]    Compiling futures-macro v0.3.27
[INFO] [stderr]    Compiling tokio-macros v1.8.2
[INFO] [stderr]    Compiling derive_more v0.99.17
[INFO] [stderr]    Compiling soku v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/sudoku.rs:645:5
[INFO] [stdout]     |
[INFO] [stdout] 645 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, foreign functions, functions, inherent methods, provided trait methods, required trait methods, and traits
[INFO] [stdout]     = note: `#[warn(unused_attributes)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/sudoku.rs:142:13
[INFO] [stdout]     |
[INFO] [stdout] 142 |         let mut cell = self.cell_mut(i.into_index())?;
[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/sudoku.rs:153:13
[INFO] [stdout]     |
[INFO] [stdout] 153 |         let mut cell = self.cell_mut(i.into_index())?;
[INFO] [stdout]     |             ----^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling futures-executor v0.3.27
[INFO] [stderr]    Compiling futures v0.3.27
[INFO] [stdout] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stdout]    --> src/sudoku.rs:645:5
[INFO] [stdout]     |
[INFO] [stdout] 645 |     #[must_use]
[INFO] [stdout]     |     ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = help: `#[must_use]` can be applied to data types, foreign functions, functions, inherent methods, provided trait methods, required trait methods, and traits
[INFO] [stdout]     = note: `#[warn(unused_attributes)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/sudoku.rs:142:13
[INFO] [stdout]     |
[INFO] [stdout] 142 |         let mut cell = self.cell_mut(i.into_index())?;
[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/sudoku.rs:153:13
[INFO] [stdout]     |
[INFO] [stdout] 153 |         let mut cell = self.cell_mut(i.into_index())?;
[INFO] [stdout]     |             ----^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 14.95s
[INFO] running `Command { std: "docker" "inspect" "c5774077820073dc13ef0f8d4360de1e0a41279c28edadac4c40249e096fea74", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c5774077820073dc13ef0f8d4360de1e0a41279c28edadac4c40249e096fea74", kill_on_drop: false }`
[INFO] [stdout] c5774077820073dc13ef0f8d4360de1e0a41279c28edadac4c40249e096fea74
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 789756813eba5c58a3cb4e92f4c41f0bcb68eba982539caed9cc0d6f62de9dcb
[INFO] running `Command { std: "docker" "start" "-a" "789756813eba5c58a3cb4e92f4c41f0bcb68eba982539caed9cc0d6f62de9dcb", kill_on_drop: false }`
[INFO] [stderr] warning: `#[must_use]` attribute cannot be used on trait methods in impl blocks
[INFO] [stderr]    --> src/sudoku.rs:645:5
[INFO] [stderr]     |
[INFO] [stderr] 645 |     #[must_use]
[INFO] [stderr]     |     ^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stderr]     = help: `#[must_use]` can be applied to data types, foreign functions, functions, inherent methods, provided trait methods, required trait methods, and traits
[INFO] [stderr]     = note: `#[warn(unused_attributes)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/sudoku.rs:142:13
[INFO] [stderr]     |
[INFO] [stderr] 142 |         let mut cell = self.cell_mut(i.into_index())?;
[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/sudoku.rs:153:13
[INFO] [stderr]     |
[INFO] [stderr] 153 |         let mut cell = self.cell_mut(i.into_index())?;
[INFO] [stderr]     |             ----^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: `soku` (lib) generated 3 warnings (run `cargo fix --lib -p soku` to apply 3 suggestions)
[INFO] [stderr] warning: `soku` (lib test) generated 3 warnings (3 duplicates)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.08s
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/soku-0cf6099c025a05cd)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests soku
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "789756813eba5c58a3cb4e92f4c41f0bcb68eba982539caed9cc0d6f62de9dcb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "789756813eba5c58a3cb4e92f4c41f0bcb68eba982539caed9cc0d6f62de9dcb", kill_on_drop: false }`
[INFO] [stdout] 789756813eba5c58a3cb4e92f4c41f0bcb68eba982539caed9cc0d6f62de9dcb
