[INFO] cloning repository https://github.com/eR3R3/rust-linked-list
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/eR3R3/rust-linked-list" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FeR3R3%2Frust-linked-list", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FeR3R3%2Frust-linked-list'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a9ab4366485886109306b70f17db4e6cfe9a4ea2
[INFO] checking eR3R3/rust-linked-list against try#b8ee37b59c6e1f39bae18b85e057975ab0d89308 for pr-139587-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FeR3R3%2Frust-linked-list" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/eR3R3/rust-linked-list on toolchain b8ee37b59c6e1f39bae18b85e057975ab0d89308
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b8ee37b59c6e1f39bae18b85e057975ab0d89308" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/eR3R3/rust-linked-list
[INFO] finished tweaking git repo https://github.com/eR3R3/rust-linked-list
[INFO] tweaked toml for git repo https://github.com/eR3R3/rust-linked-list written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/eR3R3/rust-linked-list 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" "+b8ee37b59c6e1f39bae18b85e057975ab0d89308" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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:b0b074c097205a61b89e8ad263052f976b2b332c4dc5f02aef1fe52501660d6e" "/opt/rustwide/cargo-home/bin/cargo" "+b8ee37b59c6e1f39bae18b85e057975ab0d89308" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] Error response from daemon: mkdir /var/lib/docker/overlay2/eb12ca7935289e7051f297a61975e6a55ff4cf0caecf69bfbbdd428204f14288-init/merged/dev/shm: no space left on device
[INFO] checking eR3R3/rust-linked-list against try#b8ee37b59c6e1f39bae18b85e057975ab0d89308 for pr-139587-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FeR3R3%2Frust-linked-list" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/eR3R3/rust-linked-list on toolchain b8ee37b59c6e1f39bae18b85e057975ab0d89308
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b8ee37b59c6e1f39bae18b85e057975ab0d89308" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/eR3R3/rust-linked-list
[INFO] finished tweaking git repo https://github.com/eR3R3/rust-linked-list
[INFO] tweaked toml for git repo https://github.com/eR3R3/rust-linked-list written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/eR3R3/rust-linked-list 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" "+b8ee37b59c6e1f39bae18b85e057975ab0d89308" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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:b0b074c097205a61b89e8ad263052f976b2b332c4dc5f02aef1fe52501660d6e" "/opt/rustwide/cargo-home/bin/cargo" "+b8ee37b59c6e1f39bae18b85e057975ab0d89308" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0819fe2a98b78ba3235163d7584190887a7549f3d0018ba3c86b3c712630b80e
[INFO] running `Command { std: "docker" "start" "-a" "0819fe2a98b78ba3235163d7584190887a7549f3d0018ba3c86b3c712630b80e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0819fe2a98b78ba3235163d7584190887a7549f3d0018ba3c86b3c712630b80e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0819fe2a98b78ba3235163d7584190887a7549f3d0018ba3c86b3c712630b80e", kill_on_drop: false }`
[INFO] [stdout] 0819fe2a98b78ba3235163d7584190887a7549f3d0018ba3c86b3c712630b80e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "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:b0b074c097205a61b89e8ad263052f976b2b332c4dc5f02aef1fe52501660d6e" "/opt/rustwide/cargo-home/bin/cargo" "+b8ee37b59c6e1f39bae18b85e057975ab0d89308" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e5e9fa85f71c68422df3f985dcb7f6a2344175ea1c85a3a7fbfa9efca32b869d
[INFO] running `Command { std: "docker" "start" "-a" "e5e9fa85f71c68422df3f985dcb7f6a2344175ea1c85a3a7fbfa9efca32b869d", kill_on_drop: false }`
[INFO] [stderr]     Checking linked-list v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `result`
[INFO] [stdout]   --> src/single_linked_list.rs:57:17
[INFO] [stdout]    |
[INFO] [stdout] 57 |             let result = self.head.as_ref().unwrap().value;
[INFO] [stdout]    |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_result`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `result`
[INFO] [stdout]   --> src/single_linked_list.rs:57:17
[INFO] [stdout]    |
[INFO] [stdout] 57 |             let result = self.head.as_ref().unwrap().value;
[INFO] [stdout]    |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_result`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `pop_back` is never used
[INFO] [stdout]   --> src/single_linked_list.rs:53:12
[INFO] [stdout]    |
[INFO] [stdout] 22 | impl<T: Display + Copy + Clone> List<T> {
[INFO] [stdout]    | --------------------------------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 53 |     pub fn pop_back(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `pop_back` is never used
[INFO] [stdout]   --> src/single_linked_list.rs:53:12
[INFO] [stdout]    |
[INFO] [stdout] 22 | impl<T: Display + Copy + Clone> List<T> {
[INFO] [stdout]    | --------------------------------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 53 |     pub fn pop_back(&mut self) -> Option<T> {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.09s
[INFO] running `Command { std: "docker" "inspect" "e5e9fa85f71c68422df3f985dcb7f6a2344175ea1c85a3a7fbfa9efca32b869d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e5e9fa85f71c68422df3f985dcb7f6a2344175ea1c85a3a7fbfa9efca32b869d", kill_on_drop: false }`
[INFO] [stdout] e5e9fa85f71c68422df3f985dcb7f6a2344175ea1c85a3a7fbfa9efca32b869d