[INFO] fetching crate servant 0.1.0...
[INFO] testing servant-0.1.0 against 1.91.0 for beta-1.92-2
[INFO] extracting crate servant 0.1.0 into /workspace/builds/worker-2-tc1/source
[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-2-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate servant 0.1.0 on toolchain 1.91.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 128 packages to latest compatible versions
[INFO] [stderr]       Adding bincode v1.3.3 (available: v2.0.1)
[INFO] [stderr]       Adding futures_codec v0.3.4 (available: v0.4.1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded servant-macro v0.1.0
[INFO] [stderr]   Downloaded futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded servant-log v0.1.0
[INFO] [stderr]   Downloaded futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded ring-channel v0.7.0
[INFO] [stderr]   Downloaded futures-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded pin-project-internal v0.4.30
[INFO] [stderr]   Downloaded servant-codec v0.1.0
[INFO] [stderr]   Downloaded pin-project v0.4.30
[INFO] [stderr]   Downloaded futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded derivative v1.0.4
[INFO] [stderr]   Downloaded futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded futures_codec v0.3.4
[INFO] [stderr]   Downloaded futures-io-preview v0.3.0-alpha.19
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5746420fecfce1c10278f3fca3f211dffc2af306884e1bc1fb48a1a1dc87ca1e
[INFO] running `Command { std: "docker" "start" "-a" "5746420fecfce1c10278f3fca3f211dffc2af306884e1bc1fb48a1a1dc87ca1e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5746420fecfce1c10278f3fca3f211dffc2af306884e1bc1fb48a1a1dc87ca1e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5746420fecfce1c10278f3fca3f211dffc2af306884e1bc1fb48a1a1dc87ca1e", kill_on_drop: false }`
[INFO] [stdout] 5746420fecfce1c10278f3fca3f211dffc2af306884e1bc1fb48a1a1dc87ca1e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "RUSTDOCFLAGS=--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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b17499473a5452f4d2e1a88806bd47eb9ea822026e78074a206055a33a2a710f
[INFO] running `Command { std: "docker" "start" "-a" "b17499473a5452f4d2e1a88806bd47eb9ea822026e78074a206055a33a2a710f", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v2.0.108
[INFO] [stderr]    Compiling rustix v1.1.2
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling async-io v2.6.0
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling async-task v4.7.1
[INFO] [stderr]    Compiling event-listener-strategy v0.5.4
[INFO] [stderr]    Compiling futures-channel v0.3.31
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling pin-project-internal v0.4.30
[INFO] [stderr]    Compiling value-bag v1.11.1
[INFO] [stderr]    Compiling spin v0.5.2
[INFO] [stderr]    Compiling crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling async-channel v2.5.0
[INFO] [stderr]    Compiling async-lock v3.4.1
[INFO] [stderr]    Compiling piper v0.2.4
[INFO] [stderr]    Compiling ring v0.16.20
[INFO] [stderr]    Compiling signal-hook-registry v1.4.6
[INFO] [stderr]    Compiling humantime v1.3.0
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling async-executor v1.13.3
[INFO] [stderr]    Compiling blocking v1.6.2
[INFO] [stderr]    Compiling smallvec v0.6.14
[INFO] [stderr]    Compiling log v0.4.28
[INFO] [stderr]    Compiling bytes v0.5.6
[INFO] [stderr]    Compiling untrusted v0.7.1
[INFO] [stderr]    Compiling chrono v0.4.42
[INFO] [stderr]    Compiling async-channel v1.9.0
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling kv-log-macro v1.0.7
[INFO] [stderr]    Compiling env_logger v0.7.1
[INFO] [stderr]    Compiling futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling derivative v1.0.4
[INFO] [stderr]    Compiling servant-macro v0.1.0
[INFO] [stderr]    Compiling ring-channel v0.7.0
[INFO] [stderr]    Compiling servant-log v0.1.0
[INFO] [stderr]    Compiling pin-project v0.4.30
[INFO] [stderr]    Compiling futures-macro v0.3.31
[INFO] [stderr]    Compiling serde_derive v1.0.228
[INFO] [stderr]    Compiling futures-util v0.3.31
[INFO] [stderr]    Compiling polling v3.11.0
[INFO] [stderr]    Compiling async-signal v0.2.13
[INFO] [stderr]    Compiling async-global-executor v2.4.1
[INFO] [stderr]    Compiling async-process v2.5.0
[INFO] [stderr]    Compiling async-std v1.13.2
[INFO] [stderr]    Compiling serde v1.0.228
[INFO] [stderr]    Compiling bincode v1.3.3
[INFO] [stderr]    Compiling futures-executor v0.3.31
[INFO] [stderr]    Compiling futures v0.3.31
[INFO] [stderr]    Compiling futures_codec v0.3.4
[INFO] [stderr]    Compiling servant-codec v0.1.0
[INFO] [stderr]    Compiling servant v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/accept.rs:22:6
[INFO] [stdout]    |
[INFO] [stdout] 22 |     };
[INFO] [stdout]    |      ^ help: remove this semicolon
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(redundant_semicolons)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/adapter.rs:91:10
[INFO] [stdout]    |
[INFO] [stdout] 91 |         };
[INFO] [stdout]    |          ^ help: remove this semicolon
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `record`
[INFO] [stdout]   --> src/accept.rs:38:22
[INFO] [stdout]    |
[INFO] [stdout] 38 |                 Some(record) => unreachable!(),
[INFO] [stdout]    |                      ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: if this is intentional, prefix it with an underscore
[INFO] [stdout]    |
[INFO] [stdout] 38 |                 Some(_record) => unreachable!(),
[INFO] [stdout]    |                      +
[INFO] [stdout] help: you might have meant to pattern match on the similarly named constant `_`
[INFO] [stdout]    |
[INFO] [stdout] 38 -                 Some(record) => unreachable!(),
[INFO] [stdout] 38 +                 Some(gateway::_) => unreachable!(),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `Node` is never used
[INFO] [stdout]   --> src/list.rs:38:10
[INFO] [stdout]    |
[INFO] [stdout] 38 | pub type Node<T> = Rc<RefCell<_Node<T>>>;
[INFO] [stdout]    |          ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `List` is never constructed
[INFO] [stdout]   --> src/list.rs:40:12
[INFO] [stdout]    |
[INFO] [stdout] 40 | pub struct List<T> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: multiple associated items are never used
[INFO] [stdout]    --> src/list.rs:47:12
[INFO] [stdout]     |
[INFO] [stdout]  46 | impl<T: Clone> List<T> {
[INFO] [stdout]     | ---------------------- associated items in this implementation
[INFO] [stdout]  47 |     pub fn new() -> Self {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout]  54 |     pub fn len(&self) -> usize {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout]  57 |     pub fn top(&mut self, node: Node<T>) {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout]  81 |     pub fn bottom(&mut self, node: Node<T>) {
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 105 |     pub fn remove(&mut self, node: Node<T>) {
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 118 |     pub fn push_head(&mut self, val: T) -> Node<T> {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 134 |     pub fn push_back(&mut self, val: T) -> Node<T> {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 150 |     pub fn pop_head(&mut self) -> Option<T> {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 165 |     pub fn pop_back(&mut self) -> Option<T> {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `DEFAULT_TIMEOUT_MS` is never used
[INFO] [stdout]   --> src/servant.rs:63:7
[INFO] [stdout]    |
[INFO] [stdout] 63 | const DEFAULT_TIMEOUT_MS: usize = 5000;
[INFO] [stdout]    |       ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 32.48s
[INFO] running `Command { std: "docker" "inspect" "b17499473a5452f4d2e1a88806bd47eb9ea822026e78074a206055a33a2a710f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b17499473a5452f4d2e1a88806bd47eb9ea822026e78074a206055a33a2a710f", kill_on_drop: false }`
[INFO] [stdout] b17499473a5452f4d2e1a88806bd47eb9ea822026e78074a206055a33a2a710f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "RUSTDOCFLAGS=--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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f70b36f2d31e2e8befeb34ce973764d9cccf150b283b2ffaac54ef386712d3fc
[INFO] running `Command { std: "docker" "start" "-a" "f70b36f2d31e2e8befeb34ce973764d9cccf150b283b2ffaac54ef386712d3fc", kill_on_drop: false }`
[INFO] [stderr]    Compiling servant v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/accept.rs:22:6
[INFO] [stdout]    |
[INFO] [stdout] 22 |     };
[INFO] [stdout]    |      ^ help: remove this semicolon
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(redundant_semicolons)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/adapter.rs:91:10
[INFO] [stdout]    |
[INFO] [stdout] 91 |         };
[INFO] [stdout]    |          ^ help: remove this semicolon
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `record`
[INFO] [stdout]   --> src/accept.rs:38:22
[INFO] [stdout]    |
[INFO] [stdout] 38 |                 Some(record) => unreachable!(),
[INFO] [stdout]    |                      ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: if this is intentional, prefix it with an underscore
[INFO] [stdout]    |
[INFO] [stdout] 38 |                 Some(_record) => unreachable!(),
[INFO] [stdout]    |                      +
[INFO] [stdout] help: you might have meant to pattern match on the similarly named constant `_`
[INFO] [stdout]    |
[INFO] [stdout] 38 -                 Some(record) => unreachable!(),
[INFO] [stdout] 38 +                 Some(gateway::_) => unreachable!(),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: type alias `Node` is never used
[INFO] [stdout]   --> src/list.rs:38:10
[INFO] [stdout]    |
[INFO] [stdout] 38 | pub type Node<T> = Rc<RefCell<_Node<T>>>;
[INFO] [stdout]    |          ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `List` is never constructed
[INFO] [stdout]   --> src/list.rs:40:12
[INFO] [stdout]    |
[INFO] [stdout] 40 | pub struct List<T> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: multiple associated items are never used
[INFO] [stdout]    --> src/list.rs:47:12
[INFO] [stdout]     |
[INFO] [stdout]  46 | impl<T: Clone> List<T> {
[INFO] [stdout]     | ---------------------- associated items in this implementation
[INFO] [stdout]  47 |     pub fn new() -> Self {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout]  54 |     pub fn len(&self) -> usize {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout]  57 |     pub fn top(&mut self, node: Node<T>) {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout]  81 |     pub fn bottom(&mut self, node: Node<T>) {
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 105 |     pub fn remove(&mut self, node: Node<T>) {
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 118 |     pub fn push_head(&mut self, val: T) -> Node<T> {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 134 |     pub fn push_back(&mut self, val: T) -> Node<T> {
[INFO] [stdout]     |            ^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 150 |     pub fn pop_head(&mut self) -> Option<T> {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 165 |     pub fn pop_back(&mut self) -> Option<T> {
[INFO] [stdout]     |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `DEFAULT_TIMEOUT_MS` is never used
[INFO] [stdout]   --> src/servant.rs:63:7
[INFO] [stdout]    |
[INFO] [stdout] 63 | const DEFAULT_TIMEOUT_MS: usize = 5000;
[INFO] [stdout]    |       ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/accept.rs:22:6
[INFO] [stdout]    |
[INFO] [stdout] 22 |     };
[INFO] [stdout]    |      ^ help: remove this semicolon
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(redundant_semicolons)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> src/adapter.rs:91:10
[INFO] [stdout]    |
[INFO] [stdout] 91 |         };
[INFO] [stdout]    |          ^ help: remove this semicolon
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `record`
[INFO] [stdout]   --> src/accept.rs:38:22
[INFO] [stdout]    |
[INFO] [stdout] 38 |                 Some(record) => unreachable!(),
[INFO] [stdout]    |                      ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: if this is intentional, prefix it with an underscore
[INFO] [stdout]    |
[INFO] [stdout] 38 |                 Some(_record) => unreachable!(),
[INFO] [stdout]    |                      +
[INFO] [stdout] help: you might have meant to pattern match on the similarly named constant `_`
[INFO] [stdout]    |
[INFO] [stdout] 38 -                 Some(record) => unreachable!(),
[INFO] [stdout] 38 +                 Some(gateway::_) => unreachable!(),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `len` is never used
[INFO] [stdout]   --> src/list.rs:54:12
[INFO] [stdout]    |
[INFO] [stdout] 46 | impl<T: Clone> List<T> {
[INFO] [stdout]    | ---------------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 54 |     pub fn len(&self) -> usize {
[INFO] [stdout]    |            ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `DEFAULT_TIMEOUT_MS` is never used
[INFO] [stdout]   --> src/servant.rs:63:7
[INFO] [stdout]    |
[INFO] [stdout] 63 | const DEFAULT_TIMEOUT_MS: usize = 5000;
[INFO] [stdout]    |       ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 1.48s
[INFO] running `Command { std: "docker" "inspect" "f70b36f2d31e2e8befeb34ce973764d9cccf150b283b2ffaac54ef386712d3fc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f70b36f2d31e2e8befeb34ce973764d9cccf150b283b2ffaac54ef386712d3fc", kill_on_drop: false }`
[INFO] [stdout] f70b36f2d31e2e8befeb34ce973764d9cccf150b283b2ffaac54ef386712d3fc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "RUSTDOCFLAGS=--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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] a86fff32081d3821668d0fabff86220adc6d87acd6a7eb86c41aea0c92f8e95d
[INFO] running `Command { std: "docker" "start" "-a" "a86fff32081d3821668d0fabff86220adc6d87acd6a7eb86c41aea0c92f8e95d", kill_on_drop: false }`
[INFO] [stderr] warning: unnecessary trailing semicolon
[INFO] [stderr]   --> src/accept.rs:22:6
[INFO] [stderr]    |
[INFO] [stderr] 22 |     };
[INFO] [stderr]    |      ^ help: remove this semicolon
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(redundant_semicolons)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary trailing semicolon
[INFO] [stderr]   --> src/adapter.rs:91:10
[INFO] [stderr]    |
[INFO] [stderr] 91 |         };
[INFO] [stderr]    |          ^ help: remove this semicolon
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `record`
[INFO] [stderr]   --> src/accept.rs:38:22
[INFO] [stderr]    |
[INFO] [stderr] 38 |                 Some(record) => unreachable!(),
[INFO] [stderr]    |                      ^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] help: if this is intentional, prefix it with an underscore
[INFO] [stderr]    |
[INFO] [stderr] 38 |                 Some(_record) => unreachable!(),
[INFO] [stderr]    |                      +
[INFO] [stderr] help: you might have meant to pattern match on the similarly named constant `_`
[INFO] [stderr]    |
[INFO] [stderr] 38 -                 Some(record) => unreachable!(),
[INFO] [stderr] 38 +                 Some(gateway::_) => unreachable!(),
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: type alias `Node` is never used
[INFO] [stderr]   --> src/list.rs:38:10
[INFO] [stderr]    |
[INFO] [stderr] 38 | pub type Node<T> = Rc<RefCell<_Node<T>>>;
[INFO] [stderr]    |          ^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: struct `List` is never constructed
[INFO] [stderr]   --> src/list.rs:40:12
[INFO] [stderr]    |
[INFO] [stderr] 40 | pub struct List<T> {
[INFO] [stderr]    |            ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: multiple associated items are never used
[INFO] [stderr]    --> src/list.rs:47:12
[INFO] [stderr]     |
[INFO] [stderr]  46 | impl<T: Clone> List<T> {
[INFO] [stderr]     | ---------------------- associated items in this implementation
[INFO] [stderr]  47 |     pub fn new() -> Self {
[INFO] [stderr]     |            ^^^
[INFO] [stderr] ...
[INFO] [stderr]  54 |     pub fn len(&self) -> usize {
[INFO] [stderr]     |            ^^^
[INFO] [stderr] ...
[INFO] [stderr]  57 |     pub fn top(&mut self, node: Node<T>) {
[INFO] [stderr]     |            ^^^
[INFO] [stderr] ...
[INFO] [stderr]  81 |     pub fn bottom(&mut self, node: Node<T>) {
[INFO] [stderr]     |            ^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 105 |     pub fn remove(&mut self, node: Node<T>) {
[INFO] [stderr]     |            ^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 118 |     pub fn push_head(&mut self, val: T) -> Node<T> {
[INFO] [stderr]     |            ^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 134 |     pub fn push_back(&mut self, val: T) -> Node<T> {
[INFO] [stderr]     |            ^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 150 |     pub fn pop_head(&mut self) -> Option<T> {
[INFO] [stderr]     |            ^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 165 |     pub fn pop_back(&mut self) -> Option<T> {
[INFO] [stderr]     |            ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: constant `DEFAULT_TIMEOUT_MS` is never used
[INFO] [stderr]   --> src/servant.rs:63:7
[INFO] [stderr]    |
[INFO] [stderr] 63 | const DEFAULT_TIMEOUT_MS: usize = 5000;
[INFO] [stderr]    |       ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `servant` (lib) generated 7 warnings (run `cargo fix --lib -p servant` to apply 1 suggestion)
[INFO] [stderr] warning: method `len` is never used
[INFO] [stderr]   --> src/list.rs:54:12
[INFO] [stderr]    |
[INFO] [stderr] 46 | impl<T: Clone> List<T> {
[INFO] [stderr]    | ---------------------- method in this implementation
[INFO] [stderr] ...
[INFO] [stderr] 54 |     pub fn len(&self) -> usize {
[INFO] [stderr]    |            ^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `servant` (lib test) generated 5 warnings (4 duplicates)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.14s
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/servant-ca9d0943c8a859fc)
[INFO] [stdout] 
[INFO] [stdout] running 8 tests
[INFO] [stdout] test drop_guard::tests::deref ... ok
[INFO] [stdout] test drop_guard::tests::drop_change ... ok
[INFO] [stdout] test drop_guard::tests::it_works ... ok
[INFO] [stdout] test drop_guard::tests::keep_send_shared_data ... ok
[INFO] [stdout] test drop_guard::tests::keep_sync_shared_data ... ok
[INFO] [stdout] test list::test::test2 ... ok
[INFO] [stdout] test drop_guard::tests::deref_mut ... ok
[INFO] [stderr] error: test failed, to rerun pass `--lib`
[INFO] [stdout] test list::test::test1 ... FAILED
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout] 
[INFO] [stdout] ---- list::test::test1 stdout ----
[INFO] [stdout] [src/list.rs:197:9] &l = [1]-(|1|)
[INFO] [stdout] [src/list.rs:199:9] &l = [2]-(|4>)-(<1|)
[INFO] [stdout] [src/list.rs:201:9] &l = [3]-(|4>)-(<1>)-(<2|)
[INFO] [stdout] [src/list.rs:203:9] &l = [4]-(|5>)-(<4>)-(<1>)-(<2|)
[INFO] [stdout] [src/list.rs:205:9] &l = [5]-(|5>)-(<4>)-(<1>)-(<2>)-(<3|)
[INFO] [stdout] [src/list.rs:208:9] &l = [4]-(|5>)-(<4>)-(<2>)-(<3|)
[INFO] [stdout] [src/list.rs:210:9] &l = [2]-(|4>)-(<2>)-(<3|)
[INFO] [stdout] [src/list.rs:212:9] &l = [1]-(|4>)-(<3|)
[INFO] [stdout] 
[INFO] [stdout] thread 'list::test::test1' (30) panicked at src/list.rs:116:9:
[INFO] [stdout] attempt to subtract with overflow
[INFO] [stdout] stack backtrace:
[INFO] [stdout]    0:     0x5a09567e6ff2 - std::backtrace_rs::backtrace::libunwind::trace::h62f3c6bea0fedab3
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/../../backtrace/src/backtrace/libunwind.rs:117:9
[INFO] [stdout]    1:     0x5a09567e6ff2 - std::backtrace_rs::backtrace::trace_unsynchronized::hc41aaca6c0af0bde
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/../../backtrace/src/backtrace/mod.rs:66:14
[INFO] [stdout]    2:     0x5a09567e6ff2 - std::sys::backtrace::_print_fmt::h33ac2b97007106cc
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/sys/backtrace.rs:66:9
[INFO] [stdout]    3:     0x5a09567e6ff2 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h4e0a3aeea0f9c085
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/sys/backtrace.rs:39:26
[INFO] [stdout]    4:     0x5a09567f713f - core::fmt::rt::Argument::fmt::h1edd6a3e00b22f10
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/core/src/fmt/rt.rs:173:76
[INFO] [stdout]    5:     0x5a09567f713f - core::fmt::write::hecf68a131630c74d
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/core/src/fmt/mod.rs:1468:25
[INFO] [stdout]    6:     0x5a09567b4541 - std::io::default_write_fmt::ha6b238eff7f0ef8a
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/io/mod.rs:639:11
[INFO] [stdout]    7:     0x5a09567b4541 - std::io::Write::write_fmt::h9846fe3d2a36c1ea
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/io/mod.rs:1954:13
[INFO] [stdout]    8:     0x5a09567c0612 - std::sys::backtrace::BacktraceLock::print::h75160192768e5621
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/sys/backtrace.rs:42:9
[INFO] [stdout]    9:     0x5a09567c515f - std::panicking::default_hook::{{closure}}::h14d82797cfb1ddcb
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panicking.rs:301:27
[INFO] [stdout]   10:     0x5a09567c4ff1 - std::panicking::default_hook::h63f9bf8161c5d325
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panicking.rs:325:9
[INFO] [stdout]   11:     0x5a0956784aee - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hb8126f8384f98101
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/alloc/src/boxed.rs:1999:9
[INFO] [stdout]   12:     0x5a0956784aee - test::test_main_with_exit_callback::{{closure}}::hae96ae0cd2f2ce70
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/test/src/lib.rs:145:21
[INFO] [stdout]   13:     0x5a09567c581f - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::ha703f6686c81d0c6
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/alloc/src/boxed.rs:1999:9
[INFO] [stdout]   14:     0x5a09567c581f - std::panicking::panic_with_hook::h3173740e06bd0752
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panicking.rs:842:13
[INFO] [stdout]   15:     0x5a09567c5646 - std::panicking::panic_handler::{{closure}}::hbac492c61eb56a87
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panicking.rs:700:13
[INFO] [stdout]   16:     0x5a09567c0749 - std::sys::backtrace::__rust_end_short_backtrace::haa3eac3df9535320
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/sys/backtrace.rs:174:18
[INFO] [stdout]   17:     0x5a09567a8b7d - __rustc[de0091b922c53d7e]::rust_begin_unwind
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panicking.rs:698:5
[INFO] [stdout]   18:     0x5a09567feaf0 - core::panicking::panic_fmt::h5138da2ef87be35b
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/core/src/panicking.rs:75:14
[INFO] [stdout]   19:     0x5a09567fe6d7 - core::panicking::panic_const::panic_const_sub_overflow::hf512496786ed9e49
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/core/src/panicking.rs:175:17
[INFO] [stdout]   20:     0x5a09567609eb - servant::list::List<T>::remove::h149fead2424b5b33
[INFO] [stdout]                                at /opt/rustwide/workdir/src/list.rs:116:9
[INFO] [stdout]   21:     0x5a0956762578 - servant::list::test::test1::h2a6db2913532d5c8
[INFO] [stdout]                                at /opt/rustwide/workdir/src/list.rs:213:11
[INFO] [stdout]   22:     0x5a09567627b7 - servant::list::test::test1::{{closure}}::hec4e7b76276cf1c4
[INFO] [stdout]                                at /opt/rustwide/workdir/src/list.rs:189:15
[INFO] [stdout]   23:     0x5a095675b936 - core::ops::function::FnOnce::call_once::h575613d8f77384c2
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/core/src/ops/function.rs:250:5
[INFO] [stdout]   24:     0x5a09567848cb - core::ops::function::FnOnce::call_once::h8f50ae93d93b62b4
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/core/src/ops/function.rs:250:5
[INFO] [stdout]   25:     0x5a09567848cb - test::__rust_begin_short_backtrace::h447963718d05a644
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/test/src/lib.rs:663:18
[INFO] [stdout]   26:     0x5a095679a505 - test::run_test_in_process::{{closure}}::hf890ba4755ca86c0
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/test/src/lib.rs:686:74
[INFO] [stdout]   27:     0x5a095679a505 - <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::h31e4b2860e583faa
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/core/src/panic/unwind_safe.rs:274:9
[INFO] [stdout]   28:     0x5a095679a505 - std::panicking::catch_unwind::do_call::hec7cdbbe797e2cab
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panicking.rs:590:40
[INFO] [stdout]   29:     0x5a095679a505 - std::panicking::catch_unwind::h24d3b93458b5ba67
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panicking.rs:553:19
[INFO] [stdout]   30:     0x5a095679a505 - std::panic::catch_unwind::h46eeec7cf9c9336c
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panic.rs:359:14
[INFO] [stdout]   31:     0x5a095679a505 - test::run_test_in_process::h290de6e559006104
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/test/src/lib.rs:686:27
[INFO] [stdout]   32:     0x5a095679a505 - test::run_test::{{closure}}::h26eeb2c5f7e9a995
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/test/src/lib.rs:607:43
[INFO] [stdout]   33:     0x5a0956770d04 - test::run_test::{{closure}}::h85af00882daabeaa
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/test/src/lib.rs:637:41
[INFO] [stdout]   34:     0x5a0956770d04 - std::sys::backtrace::__rust_begin_short_backtrace::h9d9305dda51fa5f2
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/sys/backtrace.rs:158:18
[INFO] [stdout]   35:     0x5a09567746aa - std::thread::Builder::spawn_unchecked_::{{closure}}::{{closure}}::hc6aada8b43f0527b
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/thread/mod.rs:559:17
[INFO] [stdout]   36:     0x5a09567746aa - <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::ha89fe5505c1206f5
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/core/src/panic/unwind_safe.rs:274:9
[INFO] [stdout]   37:     0x5a09567746aa - std::panicking::catch_unwind::do_call::he3e0bef721d99583
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panicking.rs:590:40
[INFO] [stdout]   38:     0x5a09567746aa - std::panicking::catch_unwind::ha8241964d3d773cd
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panicking.rs:553:19
[INFO] [stdout]   39:     0x5a09567746aa - std::panic::catch_unwind::ha8554bc7696cae72
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/panic.rs:359:14
[INFO] [stdout]   40:     0x5a09567746aa - std::thread::Builder::spawn_unchecked_::{{closure}}::he06f1f62b4c90f8d
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/thread/mod.rs:557:30
[INFO] [stdout]   41:     0x5a09567746aa - core::ops::function::FnOnce::call_once{{vtable.shim}}::ha7fd20ecae19b9b9
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/core/src/ops/function.rs:250:5
[INFO] [stdout]   42:     0x5a09567bb93f - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h43642ed9c40e0ab2
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/alloc/src/boxed.rs:1985:9
[INFO] [stdout]   43:     0x5a09567bb93f - std::sys::thread::unix::Thread::new::thread_start::h38da0f633f090ce2
[INFO] [stdout]                                at /rustc/f8297e351a40c1439a467bbbb6879088047f50b3/library/std/src/sys/thread/unix.rs:126:17
[INFO] [stdout]   44:     0x7a66a2a5aaa4 - <unknown>
[INFO] [stdout]   45:     0x7a66a2ae7a64 - clone
[INFO] [stdout]   46:                0x0 - <unknown>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout]     list::test::test1
[INFO] [stdout] 
[INFO] [stdout] test result: FAILED. 7 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.06s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "a86fff32081d3821668d0fabff86220adc6d87acd6a7eb86c41aea0c92f8e95d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a86fff32081d3821668d0fabff86220adc6d87acd6a7eb86c41aea0c92f8e95d", kill_on_drop: false }`
[INFO] [stdout] a86fff32081d3821668d0fabff86220adc6d87acd6a7eb86c41aea0c92f8e95d
