[INFO] cloning repository https://github.com/christiansakai/linked_list_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/christiansakai/linked_list_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchristiansakai%2Flinked_list_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchristiansakai%2Flinked_list_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b59f6d038c7a3a9c7cfb4a83a0103de5a7b175ce
[INFO] testing christiansakai/linked_list_rust against master#432e145bd5a974c5b6f4dd9b352891bd7502b69d for pr-87041
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fchristiansakai%2Flinked_list_rust" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/christiansakai/linked_list_rust on toolchain 432e145bd5a974c5b6f4dd9b352891bd7502b69d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/christiansakai/linked_list_rust
[INFO] finished tweaking git repo https://github.com/christiansakai/linked_list_rust
[INFO] tweaked toml for git repo https://github.com/christiansakai/linked_list_rust written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/christiansakai/linked_list_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9e8a7f340d1dc567c57ad2e4513b3c02b19d1d2077075eb4fe35f13eb9f767f0
[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" "9e8a7f340d1dc567c57ad2e4513b3c02b19d1d2077075eb4fe35f13eb9f767f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9e8a7f340d1dc567c57ad2e4513b3c02b19d1d2077075eb4fe35f13eb9f767f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9e8a7f340d1dc567c57ad2e4513b3c02b19d1d2077075eb4fe35f13eb9f767f0", kill_on_drop: false }`
[INFO] [stdout] 9e8a7f340d1dc567c57ad2e4513b3c02b19d1d2077075eb4fe35f13eb9f767f0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bd569074b7b805e068aaa4ba51eb39846d08d3a50c72bb0a2adf74e64ce7e5cd
[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" "bd569074b7b805e068aaa4ba51eb39846d08d3a50c72bb0a2adf74e64ce7e5cd", kill_on_drop: false }`
[INFO] [stderr]    Compiling linked_list_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]   --> src/first.rs:75:9
[INFO] [stdout]    |
[INFO] [stdout] 75 |     use super::*;
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `elem`
[INFO] [stdout]   --> src/fourth.rs:51:33
[INFO] [stdout]    |
[INFO] [stdout] 51 |     pub fn pop_front(&mut self, elem: T) -> Option<T> {
[INFO] [stdout]    |                                 ^^^^ help: if this is intentional, prefix it with an underscore: `_elem`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.75s
[INFO] running `Command { std: "docker" "inspect" "bd569074b7b805e068aaa4ba51eb39846d08d3a50c72bb0a2adf74e64ce7e5cd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bd569074b7b805e068aaa4ba51eb39846d08d3a50c72bb0a2adf74e64ce7e5cd", kill_on_drop: false }`
[INFO] [stdout] bd569074b7b805e068aaa4ba51eb39846d08d3a50c72bb0a2adf74e64ce7e5cd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f01d18be01963f49aafbde5502c8b6e10aa2a15b7b2e5a38bccf17a6ff9b28d8
[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" "f01d18be01963f49aafbde5502c8b6e10aa2a15b7b2e5a38bccf17a6ff9b28d8", kill_on_drop: false }`
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]   --> src/first.rs:75:9
[INFO] [stdout]    |
[INFO] [stdout] 75 |     use super::*;
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling linked_list_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `elem`
[INFO] [stdout]   --> src/fourth.rs:51:33
[INFO] [stdout]    |
[INFO] [stdout] 51 |     pub fn pop_front(&mut self, elem: T) -> Option<T> {
[INFO] [stdout]    |                                 ^^^^ help: if this is intentional, prefix it with an underscore: `_elem`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `elem`
[INFO] [stdout]   --> src/fourth.rs:51:33
[INFO] [stdout]    |
[INFO] [stdout] 51 |     pub fn pop_front(&mut self, elem: T) -> Option<T> {
[INFO] [stdout]    |                                 ^^^^ help: if this is intentional, prefix it with an underscore: `_elem`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.91s
[INFO] running `Command { std: "docker" "inspect" "f01d18be01963f49aafbde5502c8b6e10aa2a15b7b2e5a38bccf17a6ff9b28d8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f01d18be01963f49aafbde5502c8b6e10aa2a15b7b2e5a38bccf17a6ff9b28d8", kill_on_drop: false }`
[INFO] [stdout] f01d18be01963f49aafbde5502c8b6e10aa2a15b7b2e5a38bccf17a6ff9b28d8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 1d3a82ba8f2f724648ea207fa8486fd8ecff6c14cdb94086574e4f7e4401d14f
[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" "1d3a82ba8f2f724648ea207fa8486fd8ecff6c14cdb94086574e4f7e4401d14f", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/first.rs:75:9
[INFO] [stderr]    |
[INFO] [stderr] 75 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `elem`
[INFO] [stderr]   --> src/fourth.rs:51:33
[INFO] [stderr]    |
[INFO] [stderr] 51 |     pub fn pop_front(&mut self, elem: T) -> Option<T> {
[INFO] [stderr]    |                                 ^^^^ help: if this is intentional, prefix it with an underscore: `_elem`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 2 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `elem`
[INFO] [stderr]   --> src/fourth.rs:51:33
[INFO] [stderr]    |
[INFO] [stderr] 51 |     pub fn pop_front(&mut self, elem: T) -> Option<T> {
[INFO] [stderr]    |                                 ^^^^ help: if this is intentional, prefix it with an underscore: `_elem`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning 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_rust-0ae5e57a2e791fa6)
[INFO] [stdout] 
[INFO] [stdout] running 3 tests
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/linked_list_rust-13ab17025edc9699)
[INFO] [stdout] test third::test::iter ... ok
[INFO] [stdout] test first::test::basics ... ok
[INFO] [stdout] test third::test::basics ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests linked_list_rust
[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] [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" "1d3a82ba8f2f724648ea207fa8486fd8ecff6c14cdb94086574e4f7e4401d14f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1d3a82ba8f2f724648ea207fa8486fd8ecff6c14cdb94086574e4f7e4401d14f", kill_on_drop: false }`
[INFO] [stdout] 1d3a82ba8f2f724648ea207fa8486fd8ecff6c14cdb94086574e4f7e4401d14f