[INFO] fetching crate servant 0.1.0...
[INFO] checking servant-0.1.0 against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] extracting crate servant 0.1.0 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate servant 0.1.0 on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate servant 0.1.0
[INFO] finished tweaking crates.io crate servant 0.1.0
[INFO] tweaked toml for crates.io crate servant 0.1.0 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 550c7910bc10fb74333cf8405588fb63b5aecc29ac84a1b03ebf7848fd6057a7
[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" "550c7910bc10fb74333cf8405588fb63b5aecc29ac84a1b03ebf7848fd6057a7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "550c7910bc10fb74333cf8405588fb63b5aecc29ac84a1b03ebf7848fd6057a7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "550c7910bc10fb74333cf8405588fb63b5aecc29ac84a1b03ebf7848fd6057a7", kill_on_drop: false }`
[INFO] [stdout] 550c7910bc10fb74333cf8405588fb63b5aecc29ac84a1b03ebf7848fd6057a7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0fdb891a071bd71604fa3fb1cc8442e1afa9f7d77029bdd0cd7347e08c23096e
[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" "0fdb891a071bd71604fa3fb1cc8442e1afa9f7d77029bdd0cd7347e08c23096e", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.42
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]    Compiling serde_derive v1.0.116
[INFO] [stderr]    Compiling serde v1.0.116
[INFO] [stderr]     Checking regex-syntax v0.6.18
[INFO] [stderr]     Checking termcolor v1.1.0
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]    Compiling ring v0.16.15
[INFO] [stderr]     Checking async-channel v1.5.1
[INFO] [stderr]    Compiling derivative v1.0.4
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking nb-connect v1.0.2
[INFO] [stderr]     Checking time v0.1.44
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]     Checking futures-lite v1.10.1
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking aho-corasick v0.7.13
[INFO] [stderr]     Checking polling v2.0.0
[INFO] [stderr]     Checking kv-log-macro v1.0.7
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]     Checking async-executor v1.3.0
[INFO] [stderr]     Checking async-io v1.1.9
[INFO] [stderr]     Checking blocking v1.0.1
[INFO] [stderr]     Checking chrono v0.4.19
[INFO] [stderr]     Checking async-global-executor v1.3.0
[INFO] [stderr]     Checking async-std v1.6.5
[INFO] [stderr]     Checking regex v1.3.9
[INFO] [stderr]     Checking futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking futures-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking ring-channel v0.7.0
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]     Checking servant-log v0.1.0
[INFO] [stderr]    Compiling pin-project-internal v0.4.26
[INFO] [stderr]    Compiling futures-macro v0.3.6
[INFO] [stderr]    Compiling servant-macro v0.1.0
[INFO] [stderr]     Checking pin-project v0.4.26
[INFO] [stderr]     Checking futures-util v0.3.6
[INFO] [stderr]     Checking futures-executor v0.3.6
[INFO] [stderr]     Checking futures v0.3.6
[INFO] [stderr]     Checking futures_codec v0.3.4
[INFO] [stderr]     Checking bincode v1.3.1
[INFO] [stderr]     Checking servant-codec v0.1.0
[INFO] [stderr]     Checking servant v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `tail`
[INFO] [stdout]   --> src/list.rs:43:5
[INFO] [stdout]    |
[INFO] [stdout] 43 |     tail: Option<Node<T>>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/list.rs:47:12
[INFO] [stdout]    |
[INFO] [stdout] 47 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `len`
[INFO] [stdout]   --> src/list.rs:54:12
[INFO] [stdout]    |
[INFO] [stdout] 54 |     pub fn len(&self) -> usize {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `top`
[INFO] [stdout]   --> src/list.rs:57:12
[INFO] [stdout]    |
[INFO] [stdout] 57 |     pub fn top(&mut self, node: Node<T>) {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `bottom`
[INFO] [stdout]   --> src/list.rs:81:12
[INFO] [stdout]    |
[INFO] [stdout] 81 |     pub fn bottom(&mut self, node: Node<T>) {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `remove`
[INFO] [stdout]    --> src/list.rs:105:12
[INFO] [stdout]     |
[INFO] [stdout] 105 |     pub fn remove(&mut self, node: Node<T>) {
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `push_head`
[INFO] [stdout]    --> src/list.rs:118:12
[INFO] [stdout]     |
[INFO] [stdout] 118 |     pub fn push_head(&mut self, val: T) -> Node<T> {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `push_back`
[INFO] [stdout]    --> src/list.rs:134:12
[INFO] [stdout]     |
[INFO] [stdout] 134 |     pub fn push_back(&mut self, val: T) -> Node<T> {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `pop_head`
[INFO] [stdout]    --> src/list.rs:150:12
[INFO] [stdout]     |
[INFO] [stdout] 150 |     pub fn pop_head(&mut self) -> Option<T> {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `pop_back`
[INFO] [stdout]    --> src/list.rs:165:12
[INFO] [stdout]     |
[INFO] [stdout] 165 |     pub fn pop_back(&mut self) -> Option<T> {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `DEFAULT_TIMEOUT_MS`
[INFO] [stdout]   --> src/servant.rs:63:1
[INFO] [stdout]    |
[INFO] [stdout] 63 | const DEFAULT_TIMEOUT_MS: usize = 5000;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `len`
[INFO] [stdout]   --> src/list.rs:54:12
[INFO] [stdout]    |
[INFO] [stdout] 54 |     pub fn len(&self) -> usize {
[INFO] [stdout]    |            ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant is never used: `DEFAULT_TIMEOUT_MS`
[INFO] [stdout]   --> src/servant.rs:63:1
[INFO] [stdout]    |
[INFO] [stdout] 63 | const DEFAULT_TIMEOUT_MS: usize = 5000;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 11 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1m 35s
[INFO] running `Command { std: "docker" "inspect" "0fdb891a071bd71604fa3fb1cc8442e1afa9f7d77029bdd0cd7347e08c23096e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0fdb891a071bd71604fa3fb1cc8442e1afa9f7d77029bdd0cd7347e08c23096e", kill_on_drop: false }`
[INFO] [stdout] 0fdb891a071bd71604fa3fb1cc8442e1afa9f7d77029bdd0cd7347e08c23096e