[INFO] cloning repository https://github.com/Zheoni/sudoku
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Zheoni/sudoku" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FZheoni%2Fsudoku", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FZheoni%2Fsudoku'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 14df1b3a64c16c74d1c156db94e59c45117e4868
[INFO] building Zheoni/sudoku against master#11663cd3bfefef7d34e8f0892c250bf698049392+rustflags=-Dtail-expr-drop-order for pr-134523
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FZheoni%2Fsudoku" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Zheoni/sudoku on toolchain 11663cd3bfefef7d34e8f0892c250bf698049392
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Zheoni/sudoku
[INFO] finished tweaking git repo https://github.com/Zheoni/sudoku
[INFO] tweaked toml for git repo https://github.com/Zheoni/sudoku written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/Zheoni/sudoku 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" "+11663cd3bfefef7d34e8f0892c250bf698049392" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rand_seeder v0.2.2
[INFO] [stderr]   Downloaded rand_pcg v0.3.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3d7b97f09187d1bc4ab349ec0bc3bcbcd58975ecfbfeb1f171a9e331fb8c6b1e
[INFO] running `Command { std: "docker" "start" "-a" "3d7b97f09187d1bc4ab349ec0bc3bcbcd58975ecfbfeb1f171a9e331fb8c6b1e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3d7b97f09187d1bc4ab349ec0bc3bcbcd58975ecfbfeb1f171a9e331fb8c6b1e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3d7b97f09187d1bc4ab349ec0bc3bcbcd58975ecfbfeb1f171a9e331fb8c6b1e", kill_on_drop: false }`
[INFO] [stdout] 3d7b97f09187d1bc4ab349ec0bc3bcbcd58975ecfbfeb1f171a9e331fb8c6b1e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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 -Dtail-expr-drop-order" "-e" "RUSTDOCFLAGS=--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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3167e20c97a6f6ed22b919f68d78408ecc26d501a2b706bed8c4cde6fc94d1a6
[INFO] running `Command { std: "docker" "start" "-a" "3167e20c97a6f6ed22b919f68d78408ecc26d501a2b706bed8c4cde6fc94d1a6", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.88
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]    Compiling ppv-lite86 v0.2.10
[INFO] [stderr]    Compiling unicode-width v0.1.8
[INFO] [stderr]    Compiling ansi_term v0.11.0
[INFO] [stderr]    Compiling strsim v0.8.0
[INFO] [stderr]    Compiling vec_map v0.8.2
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling clap v2.33.3
[INFO] [stderr]    Compiling rand_core v0.6.2
[INFO] [stderr]    Compiling rand_chacha v0.3.0
[INFO] [stderr]    Compiling rand_pcg v0.3.0
[INFO] [stderr]    Compiling rand_seeder v0.2.2
[INFO] [stderr]    Compiling rand v0.8.3
[INFO] [stderr]    Compiling sudoku v1.0.6 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/sudoku.rs:42:13
[INFO] [stdout]    |
[INFO] [stdout] 42 |     IoError(io::Error),
[INFO] [stdout]    |     ------- ^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Error` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 42 |     IoError(()),
[INFO] [stdout]    |             ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/sudoku.rs:43:18
[INFO] [stdout]    |
[INFO] [stdout] 43 |     ErrorMessage(&'static str),
[INFO] [stdout]    |     ------------ ^^^^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Error` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 43 |     ErrorMessage(()),
[INFO] [stdout]    |                  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.61s
[INFO] running `Command { std: "docker" "inspect" "3167e20c97a6f6ed22b919f68d78408ecc26d501a2b706bed8c4cde6fc94d1a6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3167e20c97a6f6ed22b919f68d78408ecc26d501a2b706bed8c4cde6fc94d1a6", kill_on_drop: false }`
[INFO] [stdout] 3167e20c97a6f6ed22b919f68d78408ecc26d501a2b706bed8c4cde6fc94d1a6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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 -Dtail-expr-drop-order" "-e" "RUSTDOCFLAGS=--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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 01bab964157f41934a1709cd4c2a842a50b0ed1ceb26a5163e4b2dd69b33ba2d
[INFO] running `Command { std: "docker" "start" "-a" "01bab964157f41934a1709cd4c2a842a50b0ed1ceb26a5163e4b2dd69b33ba2d", kill_on_drop: false }`
[INFO] [stderr]    Compiling sudoku v1.0.6 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/sudoku.rs:42:13
[INFO] [stdout]    |
[INFO] [stdout] 42 |     IoError(io::Error),
[INFO] [stdout]    |     ------- ^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Error` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 42 |     IoError(()),
[INFO] [stdout]    |             ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/sudoku.rs:43:18
[INFO] [stdout]    |
[INFO] [stdout] 43 |     ErrorMessage(&'static str),
[INFO] [stdout]    |     ------------ ^^^^^^^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Error` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 43 |     ErrorMessage(()),
[INFO] [stdout]    |                  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.75s
[INFO] running `Command { std: "docker" "inspect" "01bab964157f41934a1709cd4c2a842a50b0ed1ceb26a5163e4b2dd69b33ba2d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "01bab964157f41934a1709cd4c2a842a50b0ed1ceb26a5163e4b2dd69b33ba2d", kill_on_drop: false }`
[INFO] [stdout] 01bab964157f41934a1709cd4c2a842a50b0ed1ceb26a5163e4b2dd69b33ba2d