[INFO] cloning repository https://github.com/7h3w1zard/rust-tcp
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/7h3w1zard/rust-tcp" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F7h3w1zard%2Frust-tcp", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F7h3w1zard%2Frust-tcp'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1023ca3e052908482663f0635ce0373336340845
[INFO] checking 7h3w1zard/rust-tcp against master#c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38 for pr-146470
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F7h3w1zard%2Frust-tcp" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/7h3w1zard/rust-tcp
[INFO] finished tweaking git repo https://github.com/7h3w1zard/rust-tcp
[INFO] tweaked toml for git repo https://github.com/7h3w1zard/rust-tcp written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/7h3w1zard/rust-tcp on toolchain c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/7h3w1zard/rust-tcp 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" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded autocfg v1.5.0
[INFO] [stderr]   Downloaded parking_lot_core v0.6.3
[INFO] [stderr]   Downloaded futures v0.1.31
[INFO] [stderr]   Downloaded tokio-codec v0.1.2
[INFO] [stderr]   Downloaded tokio-executor v0.1.10
[INFO] [stderr]   Downloaded tokio-core v0.1.18
[INFO] [stderr]   Downloaded net2 v0.2.39
[INFO] [stderr]   Downloaded crossbeam-epoch v0.8.2
[INFO] [stderr]   Downloaded semver v0.9.0
[INFO] [stderr]   Downloaded parking_lot v0.9.0
[INFO] [stderr]   Downloaded tun-tap v0.1.4
[INFO] [stderr]   Downloaded num_cpus v1.17.0
[INFO] [stderr]   Downloaded scoped-tls v0.1.2
[INFO] [stderr]   Downloaded ws2_32-sys v0.2.1
[INFO] [stderr]   Downloaded tokio-sync v0.1.8
[INFO] [stderr]   Downloaded tokio-threadpool v0.1.18
[INFO] [stderr]   Downloaded tokio-tcp v0.1.4
[INFO] [stderr]   Downloaded rustc_version v0.2.3
[INFO] [stderr]   Downloaded smallvec v0.6.14
[INFO] [stderr]   Downloaded miow v0.2.2
[INFO] [stderr]   Downloaded semver-parser v0.7.0
[INFO] [stderr]   Downloaded iovec v0.1.4
[INFO] [stderr]   Downloaded tokio-reactor v0.1.12
[INFO] [stderr]   Downloaded cfg-if v0.1.10
[INFO] [stderr]   Downloaded etherparse v0.8.3
[INFO] [stderr]   Downloaded cc v1.2.41
[INFO] [stderr]   Downloaded fuchsia-zircon-sys v0.3.3
[INFO] [stderr]   Downloaded tokio-io v0.1.13
[INFO] [stderr]   Downloaded mio v0.6.23
[INFO] [stderr]   Downloaded tokio-fs v0.1.7
[INFO] [stderr]   Downloaded tokio-timer v0.2.13
[INFO] [stderr]   Downloaded tokio-uds v0.2.7
[INFO] [stderr]   Downloaded crossbeam-deque v0.7.4
[INFO] [stderr]   Downloaded tokio-udp v0.1.6
[INFO] [stderr]   Downloaded crossbeam-utils v0.7.2
[INFO] [stderr]   Downloaded cloudabi v0.0.3
[INFO] [stderr]   Downloaded kernel32-sys v0.2.2
[INFO] [stderr]   Downloaded maybe-uninit v2.0.0
[INFO] [stderr]   Downloaded winapi-build v0.1.1
[INFO] [stderr]   Downloaded bytes v0.4.12
[INFO] [stderr]   Downloaded winapi v0.2.8
[INFO] [stderr]   Downloaded lock_api v0.3.4
[INFO] [stderr]   Downloaded fuchsia-zircon v0.3.3
[INFO] [stderr]   Downloaded tokio-current-thread v0.1.7
[INFO] [stderr]   Downloaded memoffset v0.5.6
[INFO] [stderr]   Downloaded redox_syscall v0.1.57
[INFO] [stderr]   Downloaded mio-uds v0.6.8
[INFO] [stderr]   Downloaded crossbeam-queue v0.2.3
[INFO] [stderr]   Downloaded hermit-abi v0.5.2
[INFO] [stderr]   Downloaded tokio v0.1.22
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fe7cc5c83e53e375a7fc1c3cfd8f2a51c0ad77e70590eb3c2ec223b68749cbc3
[INFO] running `Command { std: "docker" "start" "-a" "fe7cc5c83e53e375a7fc1c3cfd8f2a51c0ad77e70590eb3c2ec223b68749cbc3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fe7cc5c83e53e375a7fc1c3cfd8f2a51c0ad77e70590eb3c2ec223b68749cbc3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fe7cc5c83e53e375a7fc1c3cfd8f2a51c0ad77e70590eb3c2ec223b68749cbc3", kill_on_drop: false }`
[INFO] [stdout] fe7cc5c83e53e375a7fc1c3cfd8f2a51c0ad77e70590eb3c2ec223b68749cbc3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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=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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 467b541ba6f0c45ca9e99cbac132df302fbe29358a500271eab7ae3ed511d36d
[INFO] running `Command { std: "docker" "start" "-a" "467b541ba6f0c45ca9e99cbac132df302fbe29358a500271eab7ae3ed511d36d", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.5.0
[INFO] [stderr]    Compiling libc v0.2.177
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]     Checking lazy_static v1.5.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]     Checking futures v0.1.31
[INFO] [stderr]     Checking scopeguard v1.2.0
[INFO] [stderr]     Checking log v0.4.28
[INFO] [stderr]     Checking slab v0.4.11
[INFO] [stderr]     Checking byteorder v1.5.0
[INFO] [stderr]     Checking fnv v1.0.7
[INFO] [stderr]    Compiling find-msvc-tools v0.1.4
[INFO] [stderr]     Checking scoped-tls v0.1.2
[INFO] [stderr]     Checking lock_api v0.3.4
[INFO] [stderr]    Compiling cc v1.2.41
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]     Checking etherparse v0.8.3
[INFO] [stderr]     Checking smallvec v0.6.14
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling memoffset v0.5.6
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling parking_lot_core v0.6.3
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]     Checking crossbeam-queue v0.2.3
[INFO] [stderr]     Checking tokio-executor v0.1.10
[INFO] [stderr]     Checking tokio-sync v0.1.8
[INFO] [stderr]     Checking crossbeam-deque v0.7.4
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking num_cpus v1.17.0
[INFO] [stderr]     Checking net2 v0.2.39
[INFO] [stderr]     Checking tokio-timer v0.2.13
[INFO] [stderr]     Checking tokio-current-thread v0.1.7
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]    Compiling tun-tap v0.1.4
[INFO] [stderr]     Checking tokio-threadpool v0.1.18
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]     Checking tokio-io v0.1.13
[INFO] [stderr]     Checking tokio-codec v0.1.2
[INFO] [stderr]     Checking tokio-fs v0.1.7
[INFO] [stderr]     Checking tokio-reactor v0.1.12
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]     Checking tokio-uds v0.2.7
[INFO] [stderr]     Checking tokio-tcp v0.1.4
[INFO] [stderr]     Checking tokio-udp v0.1.6
[INFO] [stderr]     Checking tokio v0.1.22
[INFO] [stderr]     Checking tokio-core v0.1.18
[INFO] [stderr]     Checking trust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tcp.rs:88:13
[INFO] [stdout]    |
[INFO] [stdout] 88 |         let mut buf = [0u8; 1500];
[INFO] [stdout]    |             ----^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/tcp.rs:88:13
[INFO] [stdout]    |
[INFO] [stdout] 88 |         let mut buf = [0u8; 1500];
[INFO] [stdout]    |             ----^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/tcp.rs:135:13
[INFO] [stdout]     |
[INFO] [stdout] 135 |         let mut syn_ack = etherparse::TcpHeader::new(
[INFO] [stdout]     |             ----^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/tcp.rs:135:13
[INFO] [stdout]     |
[INFO] [stdout] 135 |         let mut syn_ack = etherparse::TcpHeader::new(
[INFO] [stdout]     |             ----^^^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `data`
[INFO] [stdout]   --> src/tcp.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         data: &'a [u8],
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_data`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `data`
[INFO] [stdout]   --> src/tcp.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         data: &'a [u8],
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_data`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `buf`
[INFO] [stdout]   --> src/tcp.rs:88:13
[INFO] [stdout]    |
[INFO] [stdout] 88 |         let mut buf = [0u8; 1500];
[INFO] [stdout]    |             ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_buf`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `buf`
[INFO] [stdout]   --> src/tcp.rs:88:13
[INFO] [stdout]    |
[INFO] [stdout] 88 |         let mut buf = [0u8; 1500];
[INFO] [stdout]    |             ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_buf`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `syn_ack`
[INFO] [stdout]    --> src/tcp.rs:135:13
[INFO] [stdout]     |
[INFO] [stdout] 135 |         let mut syn_ack = etherparse::TcpHeader::new(
[INFO] [stdout]     |             ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_syn_ack`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `syn_ack`
[INFO] [stdout]    --> src/tcp.rs:135:13
[INFO] [stdout]     |
[INFO] [stdout] 135 |         let mut syn_ack = etherparse::TcpHeader::new(
[INFO] [stdout]     |             ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_syn_ack`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iph`
[INFO] [stdout]    --> src/tcp.rs:197:9
[INFO] [stdout]     |
[INFO] [stdout] 197 |         iph: etherparse::Ipv4HeaderSlice<'a>,
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_iph`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iph`
[INFO] [stdout]    --> src/tcp.rs:197:9
[INFO] [stdout]     |
[INFO] [stdout] 197 |         iph: etherparse::Ipv4HeaderSlice<'a>,
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_iph`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]   --> src/main.rs:69:17
[INFO] [stdout]    |
[INFO] [stdout] 69 |             Err(e) => {
[INFO] [stdout]    |                 ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]   --> src/main.rs:69:17
[INFO] [stdout]    |
[INFO] [stdout] 69 |             Err(e) => {
[INFO] [stdout]    |                 ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `is_synchronized` is never used
[INFO] [stdout]   --> src/tcp.rs:14:8
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl State {
[INFO] [stdout]    | ---------- method in this implementation
[INFO] [stdout] 14 |     fn is_synchronized(&self) -> bool {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `up`, `wl1`, and `wl2` are never read
[INFO] [stdout]   --> src/tcp.rs:50:5
[INFO] [stdout]    |
[INFO] [stdout] 42 | pub struct SendSequenceSpace {
[INFO] [stdout]    |            ----------------- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 50 |     up: bool,
[INFO] [stdout]    |     ^^
[INFO] [stdout] 51 |     /// - segment sequence number used for last window update
[INFO] [stdout] 52 |     wl1: usize,
[INFO] [stdout]    |     ^^^
[INFO] [stdout] 53 |     /// - segment acknowledgment number used for last window update
[INFO] [stdout] 54 |     wl2: usize,
[INFO] [stdout]    |     ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `is_synchronized` is never used
[INFO] [stdout]   --> src/tcp.rs:14:8
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl State {
[INFO] [stdout]    | ---------- method in this implementation
[INFO] [stdout] 14 |     fn is_synchronized(&self) -> bool {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `up` and `irs` are never read
[INFO] [stdout]   --> src/tcp.rs:76:5
[INFO] [stdout]    |
[INFO] [stdout] 70 | pub struct ReceiveSequenceSpace {
[INFO] [stdout]    |            -------------------- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 76 |     up: bool,
[INFO] [stdout]    |     ^^
[INFO] [stdout] 77 |     /// - initial received sequence number
[INFO] [stdout] 78 |     irs: u32,
[INFO] [stdout]    |     ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `up`, `wl1`, and `wl2` are never read
[INFO] [stdout]   --> src/tcp.rs:50:5
[INFO] [stdout]    |
[INFO] [stdout] 42 | pub struct SendSequenceSpace {
[INFO] [stdout]    |            ----------------- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 50 |     up: bool,
[INFO] [stdout]    |     ^^
[INFO] [stdout] 51 |     /// - segment sequence number used for last window update
[INFO] [stdout] 52 |     wl1: usize,
[INFO] [stdout]    |     ^^^
[INFO] [stdout] 53 |     /// - segment acknowledgment number used for last window update
[INFO] [stdout] 54 |     wl2: usize,
[INFO] [stdout]    |     ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `send_rst` is never used
[INFO] [stdout]    --> src/tcp.rs:185:8
[INFO] [stdout]     |
[INFO] [stdout]  81 | impl Connection {
[INFO] [stdout]     | --------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 185 |     fn send_rst(&mut self, nic: &mut tun_tap::Iface) -> io::Result<()> {
[INFO] [stdout]     |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `up` and `irs` are never read
[INFO] [stdout]   --> src/tcp.rs:76:5
[INFO] [stdout]    |
[INFO] [stdout] 70 | pub struct ReceiveSequenceSpace {
[INFO] [stdout]    |            -------------------- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 76 |     up: bool,
[INFO] [stdout]    |     ^^
[INFO] [stdout] 77 |     /// - initial received sequence number
[INFO] [stdout] 78 |     irs: u32,
[INFO] [stdout]    |     ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `send_rst` is never used
[INFO] [stdout]    --> src/tcp.rs:185:8
[INFO] [stdout]     |
[INFO] [stdout]  81 | impl Connection {
[INFO] [stdout]     | --------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 185 |     fn send_rst(&mut self, nic: &mut tun_tap::Iface) -> io::Result<()> {
[INFO] [stdout]     |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:156:9
[INFO] [stdout]     |
[INFO] [stdout] 156 |         self.ip.set_payload_len(size - self.ip.header_len() as usize);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 156 |         let _ = self.ip.set_payload_len(size - self.ip.header_len() as usize);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:156:9
[INFO] [stdout]     |
[INFO] [stdout] 156 |         self.ip.set_payload_len(size - self.ip.header_len() as usize);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 156 |         let _ = self.ip.set_payload_len(size - self.ip.header_len() as usize);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:168:9
[INFO] [stdout]     |
[INFO] [stdout] 168 |         self.ip.write(&mut unwritten);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 168 |         let _ = self.ip.write(&mut unwritten);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:168:9
[INFO] [stdout]     |
[INFO] [stdout] 168 |         self.ip.write(&mut unwritten);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 168 |         let _ = self.ip.write(&mut unwritten);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `core::num::<impl u32>::wrapping_add` that must be used
[INFO] [stdout]    --> src/tcp.rs:172:9
[INFO] [stdout]     |
[INFO] [stdout] 172 |         self.send.nxt.wrapping_add(payload_bytes as u32);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this returns the result of the operation, without modifying the original
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 172 |         let _ = self.send.nxt.wrapping_add(payload_bytes as u32);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `core::num::<impl u32>::wrapping_add` that must be used
[INFO] [stdout]    --> src/tcp.rs:172:9
[INFO] [stdout]     |
[INFO] [stdout] 172 |         self.send.nxt.wrapping_add(payload_bytes as u32);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this returns the result of the operation, without modifying the original
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 172 |         let _ = self.send.nxt.wrapping_add(payload_bytes as u32);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.98s
[INFO] running `Command { std: "docker" "inspect" "467b541ba6f0c45ca9e99cbac132df302fbe29358a500271eab7ae3ed511d36d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "467b541ba6f0c45ca9e99cbac132df302fbe29358a500271eab7ae3ed511d36d", kill_on_drop: false }`
[INFO] [stdout] 467b541ba6f0c45ca9e99cbac132df302fbe29358a500271eab7ae3ed511d36d
