[INFO] updating cached repository https://github.com/khionu/sudoku_solver
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 84c98ab4002e56403bfe6b0a2a58a56d968eddf9
[INFO] testing khionu/sudoku_solver against master#8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e for pr-74409
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkhionu%2Fsudoku_solver" "/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/khionu/sudoku_solver on toolchain 8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/khionu/sudoku_solver
[INFO] finished tweaking git repo https://github.com/khionu/sudoku_solver
[INFO] tweaked toml for git repo https://github.com/khionu/sudoku_solver written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate git repo https://github.com/khionu/sudoku_solver already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d613d3694a028ac76ff25a3f8ff4d07cf387ea95a0630f794c24b92b1330e371
[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" "d613d3694a028ac76ff25a3f8ff4d07cf387ea95a0630f794c24b92b1330e371", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d613d3694a028ac76ff25a3f8ff4d07cf387ea95a0630f794c24b92b1330e371", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d613d3694a028ac76ff25a3f8ff4d07cf387ea95a0630f794c24b92b1330e371", kill_on_drop: false }`
[INFO] [stdout] d613d3694a028ac76ff25a3f8ff4d07cf387ea95a0630f794c24b92b1330e371
[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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 120247b6bbe449569c3013e9132ed87ac63f85dc954b85959564fe79a8b10ca6
[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" "120247b6bbe449569c3013e9132ed87ac63f85dc954b85959564fe79a8b10ca6", kill_on_drop: false }`
[INFO] [stderr]    Compiling cfg-if v0.1.9
[INFO] [stderr]    Compiling lazy_static v1.3.0
[INFO] [stderr]    Compiling arrayvec v0.4.10
[INFO] [stderr]    Compiling nodrop v0.1.13
[INFO] [stderr]    Compiling memoffset v0.2.1
[INFO] [stderr]    Compiling scopeguard v0.3.3
[INFO] [stderr]    Compiling either v1.5.2
[INFO] [stderr]    Compiling crossbeam-utils v0.6.5
[INFO] [stderr]    Compiling itertools v0.8.0
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling crossbeam-channel v0.3.8
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.1
[INFO] [stderr]    Compiling crossbeam-deque v0.6.3
[INFO] [stderr]    Compiling rayon-core v1.5.0
[INFO] [stderr]    Compiling rayon v1.1.0
[INFO] [stderr]    Compiling sudoku_solver v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0599]: no function or associated item named `from_str` found for type `usize` in the current scope
[INFO] [stdout]   --> src/main.rs:75:26
[INFO] [stdout]    |
[INFO] [stdout] 75 |     let threads = usize::from_str(std::env::var("RUST_SUDOKU_THREADS")
[INFO] [stdout]    |                          ^^^^^^^^ function or associated item not found in `usize`
[INFO] [stdout]    |
[INFO] [stdout]    = help: items from traits can only be used if the trait is in scope
[INFO] [stdout] help: the following trait is implemented but not in scope; perhaps add a `use` for it:
[INFO] [stdout]    |
[INFO] [stdout] 3  | use std::str::FromStr;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0599`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `sudoku_solver`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "120247b6bbe449569c3013e9132ed87ac63f85dc954b85959564fe79a8b10ca6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "120247b6bbe449569c3013e9132ed87ac63f85dc954b85959564fe79a8b10ca6", kill_on_drop: false }`
[INFO] [stdout] 120247b6bbe449569c3013e9132ed87ac63f85dc954b85959564fe79a8b10ca6