[INFO] cloning repository https://github.com/henryroyal/tcprust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/henryroyal/tcprust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhenryroyal%2Ftcprust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhenryroyal%2Ftcprust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6def23ebc3123e45582b9dee3f615eea4e589a9f
[INFO] checking henryroyal/tcprust against master#bca37a20bd376ce3fd138e7cdee7fe704e0f8814 for pr-139493-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhenryroyal%2Ftcprust" "/workspace/builds/worker-1-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/henryroyal/tcprust
[INFO] finished tweaking git repo https://github.com/henryroyal/tcprust
[INFO] tweaked toml for git repo https://github.com/henryroyal/tcprust written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/henryroyal/tcprust on toolchain bca37a20bd376ce3fd138e7cdee7fe704e0f8814
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/henryroyal/tcprust 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" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded tokio-threadpool v0.1.16
[INFO] [stderr]   Downloaded tokio-reactor v0.1.10
[INFO] [stderr]   Downloaded tokio-core v0.1.17
[INFO] [stderr]   Downloaded etherparse v0.8.2
[INFO] [stderr]   Downloaded tun-tap v0.1.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:aa71247004a7fa38d13ec170f48f06cdedf5bc50b2a8645e56ed7e992e6fa513" "/opt/rustwide/cargo-home/bin/cargo" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4dcced1880bf59b3ead7d4866fbf9f075b891da4eaca438b78494bb35ff0b657
[INFO] running `Command { std: "docker" "start" "-a" "4dcced1880bf59b3ead7d4866fbf9f075b891da4eaca438b78494bb35ff0b657", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4dcced1880bf59b3ead7d4866fbf9f075b891da4eaca438b78494bb35ff0b657", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4dcced1880bf59b3ead7d4866fbf9f075b891da4eaca438b78494bb35ff0b657", kill_on_drop: false }`
[INFO] [stdout] 4dcced1880bf59b3ead7d4866fbf9f075b891da4eaca438b78494bb35ff0b657
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:aa71247004a7fa38d13ec170f48f06cdedf5bc50b2a8645e56ed7e992e6fa513" "/opt/rustwide/cargo-home/bin/cargo" "+bca37a20bd376ce3fd138e7cdee7fe704e0f8814" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b1a8f6ecae6cda3aa2744c1756699c6d53d941c4d015ae20a4ba15adaad5935a
[INFO] running `Command { std: "docker" "start" "-a" "b1a8f6ecae6cda3aa2744c1756699c6d53d941c4d015ae20a4ba15adaad5935a", kill_on_drop: false }`
[INFO] [stderr]     Checking futures v0.1.29
[INFO] [stderr]     Checking scopeguard v1.0.0
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]     Checking smallvec v0.6.10
[INFO] [stderr]     Checking fnv v1.0.6
[INFO] [stderr]    Compiling cc v1.0.46
[INFO] [stderr]     Checking scoped-tls v0.1.2
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]     Checking crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling parking_lot_core v0.6.2
[INFO] [stderr]    Compiling memoffset v0.5.1
[INFO] [stderr]     Checking etherparse v0.8.2
[INFO] [stderr]     Checking lock_api v0.3.1
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking num_cpus v1.10.1
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking crossbeam-epoch v0.7.2
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]    Compiling tun-tap v0.1.2
[INFO] [stderr]     Checking parking_lot v0.9.0
[INFO] [stderr]     Checking mio v0.6.19
[INFO] [stderr]     Checking crossbeam-deque v0.7.1
[INFO] [stderr]     Checking tokio-executor v0.1.8
[INFO] [stderr]     Checking tokio-sync v0.1.7
[INFO] [stderr]     Checking tokio-io v0.1.12
[INFO] [stderr]     Checking tokio-threadpool v0.1.16
[INFO] [stderr]     Checking tokio-timer v0.2.11
[INFO] [stderr]     Checking tokio-current-thread v0.1.6
[INFO] [stderr]     Checking mio-uds v0.6.7
[INFO] [stderr]     Checking tokio-codec v0.1.1
[INFO] [stderr]     Checking tokio-reactor v0.1.10
[INFO] [stderr]     Checking tokio-fs v0.1.6
[INFO] [stderr]     Checking tokio-tcp v0.1.3
[INFO] [stderr]     Checking tokio-uds v0.2.5
[INFO] [stderr]     Checking tokio-udp v0.1.5
[INFO] [stderr]     Checking tokio v0.1.22
[INFO] [stderr]     Checking tokio-core v0.1.17
[INFO] [stderr]     Checking tcprust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/tcp.rs:167:13
[INFO] [stdout]     |
[INFO] [stdout] 167 |         let mut ip = Ipv4Header::new(
[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:201:13
[INFO] [stdout]     |
[INFO] [stdout] 201 |         let mut unwritten = &mut buf[..];
[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:202:13
[INFO] [stdout]     |
[INFO] [stdout] 202 |         let mut written = 0;
[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:204:13
[INFO] [stdout]     |
[INFO] [stdout] 204 |         let mut unwritten = {
[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:143:9
[INFO] [stdout]     |
[INFO] [stdout] 143 |         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: `unwritten`
[INFO] [stdout]    --> src/tcp.rs:201:13
[INFO] [stdout]     |
[INFO] [stdout] 201 |         let mut unwritten = &mut buf[..];
[INFO] [stdout]     |             ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unwritten`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `written`
[INFO] [stdout]    --> src/tcp.rs:202:13
[INFO] [stdout]     |
[INFO] [stdout] 202 |         let mut written = 0;
[INFO] [stdout]     |             ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_written`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `nic`
[INFO] [stdout]    --> src/tcp.rs:217:9
[INFO] [stdout]     |
[INFO] [stdout] 217 |         nic: &mut Iface,
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_nic`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iph`
[INFO] [stdout]    --> src/tcp.rs:218:9
[INFO] [stdout]     |
[INFO] [stdout] 218 |         iph: Ipv4HeaderSlice<'a>,
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_iph`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:49:43
[INFO] [stdout]    |
[INFO] [stdout] 49 | ...                   Entry::Vacant(mut ve) => {
[INFO] [stdout]    |                                     ----^^
[INFO] [stdout]    |                                     |
[INFO] [stdout]    |                                     help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:199:9
[INFO] [stdout]     |
[INFO] [stdout] 199 |         c.ip.set_payload_len(syn_ack.header_len() as usize + 0); // 0 is len of data
[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] 199 |         let _ = c.ip.set_payload_len(syn_ack.header_len() as usize + 0); // 0 is len of data
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:206:13
[INFO] [stdout]     |
[INFO] [stdout] 206 |             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] 206 |             let _ = ip.write(&mut unwritten);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:207:13
[INFO] [stdout]     |
[INFO] [stdout] 207 |             syn_ack.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] 207 |             let _ = syn_ack.write(&mut unwritten);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:211:9
[INFO] [stdout]     |
[INFO] [stdout] 211 |         nic.send(&buf[..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] 211 |         let _ = nic.send(&buf[..unwritten]);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: call to `.deref()` on a reference in this situation does nothing
[INFO] [stdout]    --> src/tcp.rs:231:27
[INFO] [stdout]     |
[INFO] [stdout] 231 |         let datalen = data.deref().len() as u32;
[INFO] [stdout]     |                           ^^^^^^^^ help: remove this redundant call
[INFO] [stdout]     |
[INFO] [stdout]     = note: the type `[u8]` does not implement `Deref`, so calling `deref` on `&[u8]` copies the reference, which does not do anything and can be removed
[INFO] [stdout]     = note: `#[warn(noop_method_call)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/tcp.rs:167:13
[INFO] [stdout]     |
[INFO] [stdout] 167 |         let mut ip = Ipv4Header::new(
[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:201:13
[INFO] [stdout]     |
[INFO] [stdout] 201 |         let mut unwritten = &mut buf[..];
[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:202:13
[INFO] [stdout]     |
[INFO] [stdout] 202 |         let mut written = 0;
[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:204:13
[INFO] [stdout]     |
[INFO] [stdout] 204 |         let mut unwritten = {
[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:143:9
[INFO] [stdout]     |
[INFO] [stdout] 143 |         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: `unwritten`
[INFO] [stdout]    --> src/tcp.rs:201:13
[INFO] [stdout]     |
[INFO] [stdout] 201 |         let mut unwritten = &mut buf[..];
[INFO] [stdout]     |             ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unwritten`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `written`
[INFO] [stdout]    --> src/tcp.rs:202:13
[INFO] [stdout]     |
[INFO] [stdout] 202 |         let mut written = 0;
[INFO] [stdout]     |             ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_written`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `nic`
[INFO] [stdout]    --> src/tcp.rs:217:9
[INFO] [stdout]     |
[INFO] [stdout] 217 |         nic: &mut Iface,
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_nic`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iph`
[INFO] [stdout]    --> src/tcp.rs:218:9
[INFO] [stdout]     |
[INFO] [stdout] 218 |         iph: Ipv4HeaderSlice<'a>,
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_iph`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:49:43
[INFO] [stdout]    |
[INFO] [stdout] 49 | ...                   Entry::Vacant(mut ve) => {
[INFO] [stdout]    |                                     ----^^
[INFO] [stdout]    |                                     |
[INFO] [stdout]    |                                     help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:199:9
[INFO] [stdout]     |
[INFO] [stdout] 199 |         c.ip.set_payload_len(syn_ack.header_len() as usize + 0); // 0 is len of data
[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] 199 |         let _ = c.ip.set_payload_len(syn_ack.header_len() as usize + 0); // 0 is len of data
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:206:13
[INFO] [stdout]     |
[INFO] [stdout] 206 |             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] 206 |             let _ = ip.write(&mut unwritten);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:207:13
[INFO] [stdout]     |
[INFO] [stdout] 207 |             syn_ack.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] 207 |             let _ = syn_ack.write(&mut unwritten);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/tcp.rs:211:9
[INFO] [stdout]     |
[INFO] [stdout] 211 |         nic.send(&buf[..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] 211 |         let _ = nic.send(&buf[..unwritten]);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: call to `.deref()` on a reference in this situation does nothing
[INFO] [stdout]    --> src/tcp.rs:231:27
[INFO] [stdout]     |
[INFO] [stdout] 231 |         let datalen = data.deref().len() as u32;
[INFO] [stdout]     |                           ^^^^^^^^ help: remove this redundant call
[INFO] [stdout]     |
[INFO] [stdout]     = note: the type `[u8]` does not implement `Deref`, so calling `deref` on `&[u8]` copies the reference, which does not do anything and can be removed
[INFO] [stdout]     = note: `#[warn(noop_method_call)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.14s
[INFO] running `Command { std: "docker" "inspect" "b1a8f6ecae6cda3aa2744c1756699c6d53d941c4d015ae20a4ba15adaad5935a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b1a8f6ecae6cda3aa2744c1756699c6d53d941c4d015ae20a4ba15adaad5935a", kill_on_drop: false }`
[INFO] [stdout] b1a8f6ecae6cda3aa2744c1756699c6d53d941c4d015ae20a4ba15adaad5935a
