[INFO] cloning repository https://github.com/shivenigma/data-structures-algorithms
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/shivenigma/data-structures-algorithms" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshivenigma%2Fdata-structures-algorithms", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshivenigma%2Fdata-structures-algorithms'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1e6745b9085f7c4f0411d4bb7d0dc7ca50cef79d
[INFO] testing shivenigma/data-structures-algorithms against beta-2021-09-08 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fshivenigma%2Fdata-structures-algorithms" "/workspace/builds/worker-38/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-38/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/shivenigma/data-structures-algorithms on toolchain beta-2021-09-08
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/shivenigma/data-structures-algorithms
[INFO] finished tweaking git repo https://github.com/shivenigma/data-structures-algorithms
[INFO] tweaked toml for git repo https://github.com/shivenigma/data-structures-algorithms written to /workspace/builds/worker-38/source/Cargo.toml
[INFO] crate git repo https://github.com/shivenigma/data-structures-algorithms already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-38/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-38/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1bb58823b034f9c61eb0ddd1e64d25ef74c7f5b2a4bd10151dce30ae3a1907cf
[INFO] running `Command { std: "docker" "start" "-a" "1bb58823b034f9c61eb0ddd1e64d25ef74c7f5b2a4bd10151dce30ae3a1907cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1bb58823b034f9c61eb0ddd1e64d25ef74c7f5b2a4bd10151dce30ae3a1907cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1bb58823b034f9c61eb0ddd1e64d25ef74c7f5b2a4bd10151dce30ae3a1907cf", kill_on_drop: false }`
[INFO] [stdout] 1bb58823b034f9c61eb0ddd1e64d25ef74c7f5b2a4bd10151dce30ae3a1907cf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-38/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-38/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" "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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 579ebd733291344a5ab8edc9242b56e222f5e2e94d150b469ee5d4645b9a8376
[INFO] running `Command { std: "docker" "start" "-a" "579ebd733291344a5ab8edc9242b56e222f5e2e94d150b469ee5d4645b9a8376", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling data-structures v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::mem`
[INFO] [stdout]  --> src/ds/singly_linked_list.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::mem;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> src/ds/singly_linked_list.rs:24:33
[INFO] [stdout]    |
[INFO] [stdout] 24 |             next: Some(Box::new(next))
[INFO] [stdout]    |                                 ^^^^ expected struct `Node`, found enum `Option`
[INFO] [stdout]    |
[INFO] [stdout]    = note: expected struct `Node<_>`
[INFO] [stdout]                 found enum `Option<Node<_>>`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0308`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `data-structures` due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "579ebd733291344a5ab8edc9242b56e222f5e2e94d150b469ee5d4645b9a8376", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "579ebd733291344a5ab8edc9242b56e222f5e2e94d150b469ee5d4645b9a8376", kill_on_drop: false }`
[INFO] [stdout] 579ebd733291344a5ab8edc9242b56e222f5e2e94d150b469ee5d4645b9a8376