[INFO] cloning repository https://github.com/scrogson/linked-list-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/scrogson/linked-list-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fscrogson%2Flinked-list-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fscrogson%2Flinked-list-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f4a8134bc9afc1068719ca9e77705406fbb2f8fc
[INFO] testing scrogson/linked-list-rs against master#99e3aef02079e9c10583638520cd0c134dc3a01d for pr-85530
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fscrogson%2Flinked-list-rs" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/scrogson/linked-list-rs on toolchain 99e3aef02079e9c10583638520cd0c134dc3a01d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/scrogson/linked-list-rs
[INFO] finished tweaking git repo https://github.com/scrogson/linked-list-rs
[INFO] tweaked toml for git repo https://github.com/scrogson/linked-list-rs written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/scrogson/linked-list-rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2e46b32ae45f98f785d54c2dc3f9c4b99fe44bccf1610aac4323ed601b699480
[INFO] running `Command { std: "docker" "start" "-a" "2e46b32ae45f98f785d54c2dc3f9c4b99fe44bccf1610aac4323ed601b699480", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2e46b32ae45f98f785d54c2dc3f9c4b99fe44bccf1610aac4323ed601b699480", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2e46b32ae45f98f785d54c2dc3f9c4b99fe44bccf1610aac4323ed601b699480", kill_on_drop: false }`
[INFO] [stdout] 2e46b32ae45f98f785d54c2dc3f9c4b99fe44bccf1610aac4323ed601b699480
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "-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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6e8706f5dcf1c75277c865437c3d9f4476560cbf59a43f94a22939cb69a8cea1
[INFO] running `Command { std: "docker" "start" "-a" "6e8706f5dcf1c75277c865437c3d9f4476560cbf59a43f94a22939cb69a8cea1", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling linked-list-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `tail`
[INFO] [stdout]  --> src/fourth.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     tail: Link<T>,
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `elem`
[INFO] [stdout]   --> src/fourth.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     elem: T,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next`
[INFO] [stdout]   --> src/fourth.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     next: Link<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `prev`
[INFO] [stdout]   --> src/fourth.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     prev: Link<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.75s
[INFO] running `Command { std: "docker" "inspect" "6e8706f5dcf1c75277c865437c3d9f4476560cbf59a43f94a22939cb69a8cea1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e8706f5dcf1c75277c865437c3d9f4476560cbf59a43f94a22939cb69a8cea1", kill_on_drop: false }`
[INFO] [stdout] 6e8706f5dcf1c75277c865437c3d9f4476560cbf59a43f94a22939cb69a8cea1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "-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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a393326dc4a37dfa14cbd2bd79860417abab7759a4edec3a886ad5d5475fabad
[INFO] running `Command { std: "docker" "start" "-a" "a393326dc4a37dfa14cbd2bd79860417abab7759a4edec3a886ad5d5475fabad", kill_on_drop: false }`
[INFO] [stdout] warning: field is never read: `tail`
[INFO] [stdout]  --> src/fourth.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     tail: Link<T>,
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling linked-list-rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `elem`
[INFO] [stdout]   --> src/fourth.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     elem: T,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next`
[INFO] [stdout]   --> src/fourth.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     next: Link<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `prev`
[INFO] [stdout]   --> src/fourth.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     prev: Link<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `tail`
[INFO] [stdout]  --> src/fourth.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     tail: Link<T>,
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `elem`
[INFO] [stdout]   --> src/fourth.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     elem: T,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next`
[INFO] [stdout]   --> src/fourth.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     next: Link<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `prev`
[INFO] [stdout]   --> src/fourth.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     prev: Link<T>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.58s
[INFO] running `Command { std: "docker" "inspect" "a393326dc4a37dfa14cbd2bd79860417abab7759a4edec3a886ad5d5475fabad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a393326dc4a37dfa14cbd2bd79860417abab7759a4edec3a886ad5d5475fabad", kill_on_drop: false }`
[INFO] [stdout] a393326dc4a37dfa14cbd2bd79860417abab7759a4edec3a886ad5d5475fabad
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "-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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 7b8320da56978c4d0bd50786a44c43ded40693b7118433aacae91de7ba58dddc
[INFO] running `Command { std: "docker" "start" "-a" "7b8320da56978c4d0bd50786a44c43ded40693b7118433aacae91de7ba58dddc", kill_on_drop: false }`
[INFO] [stderr] warning: field is never read: `tail`
[INFO] [stderr]  --> src/fourth.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 |     tail: Link<T>,
[INFO] [stderr]   |     ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `elem`
[INFO] [stderr]   --> src/fourth.rs:12:5
[INFO] [stderr]    |
[INFO] [stderr] 12 |     elem: T,
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `next`
[INFO] [stderr]   --> src/fourth.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     next: Link<T>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `prev`
[INFO] [stderr]   --> src/fourth.rs:14:5
[INFO] [stderr]    |
[INFO] [stderr] 14 |     prev: Link<T>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 4 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `tail`
[INFO] [stderr]  --> src/fourth.rs:6:5
[INFO] [stderr]   |
[INFO] [stderr] 6 |     tail: Link<T>,
[INFO] [stderr]   |     ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `elem`
[INFO] [stderr]   --> src/fourth.rs:12:5
[INFO] [stderr]    |
[INFO] [stderr] 12 |     elem: T,
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `next`
[INFO] [stderr]   --> src/fourth.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     next: Link<T>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `prev`
[INFO] [stderr]   --> src/fourth.rs:14:5
[INFO] [stderr]    |
[INFO] [stderr] 14 |     prev: Link<T>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 4 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/linked_list_rs-5a54049dbdd3b29f)
[INFO] [stdout] 
[INFO] [stdout] running 8 tests
[INFO] [stdout] test second::tests::basics ... ok
[INFO] [stdout] test second::tests::into_iter ... ok
[INFO] [stdout] test second::tests::iter_mut ... ok
[INFO] [stderr]    Doc-tests linked-list-rs
[INFO] [stdout] test third::tests::basics ... ok
[INFO] [stdout] test third::tests::iter ... ok
[INFO] [stdout] test second::tests::iter ... ok
[INFO] [stdout] test second::tests::peek ... ok
[INFO] [stdout] test first::tests::basics ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 8 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[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" "7b8320da56978c4d0bd50786a44c43ded40693b7118433aacae91de7ba58dddc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b8320da56978c4d0bd50786a44c43ded40693b7118433aacae91de7ba58dddc", kill_on_drop: false }`
[INFO] [stdout] 7b8320da56978c4d0bd50786a44c43ded40693b7118433aacae91de7ba58dddc