[INFO] cloning repository https://github.com/quirinux/rust-core-utils
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/quirinux/rust-core-utils" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fquirinux%2Frust-core-utils", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fquirinux%2Frust-core-utils'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8f2ffb6576e72fb0177a1e7fb5c455c26bc62190
[INFO] checking quirinux/rust-core-utils against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fquirinux%2Frust-core-utils" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/quirinux/rust-core-utils
[INFO] finished tweaking git repo https://github.com/quirinux/rust-core-utils
[INFO] tweaked toml for git repo https://github.com/quirinux/rust-core-utils written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/quirinux/rust-core-utils on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/quirinux/rust-core-utils 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" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--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-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7553773e919d3536628296ededc1c5612548821d60ba7b664aa1525970aa25f2
[INFO] running `Command { std: "docker" "start" "-a" "7553773e919d3536628296ededc1c5612548821d60ba7b664aa1525970aa25f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7553773e919d3536628296ededc1c5612548821d60ba7b664aa1525970aa25f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7553773e919d3536628296ededc1c5612548821d60ba7b664aa1525970aa25f2", kill_on_drop: false }`
[INFO] [stdout] 7553773e919d3536628296ededc1c5612548821d60ba7b664aa1525970aa25f2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid -Dunmustuse_in_always_ok" "-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" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6a47968f69ea48fc0ab0843a211bec686ce3ee19fb48d3c3eb025556a2a1a53d
[INFO] running `Command { std: "docker" "start" "-a" "6a47968f69ea48fc0ab0843a211bec686ce3ee19fb48d3c3eb025556a2a1a53d", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.2.0
[INFO] [stderr]    Compiling syn v0.15.36
[INFO] [stderr]    Compiling unicode-segmentation v1.3.0
[INFO] [stderr]     Checking ucd-util v0.1.3
[INFO] [stderr]    Compiling regex v1.1.7
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking quick-error v1.2.2
[INFO] [stderr]     Checking smallvec v0.6.10
[INFO] [stderr]     Checking regex-syntax v0.6.7
[INFO] [stderr]     Checking utf8-ranges v1.0.3
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking humantime v1.2.0
[INFO] [stderr]     Checking crossbeam-deque v0.7.1
[INFO] [stderr]     Checking crossbeam-channel v0.3.8
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]     Checking termcolor v1.0.5
[INFO] [stderr]     Checking aho-corasick v0.7.4
[INFO] [stderr]     Checking crossbeam v0.7.1
[INFO] [stderr]    Compiling structopt-derive v0.2.16
[INFO] [stderr]     Checking env_logger v0.6.2
[INFO] [stderr]     Checking structopt v0.2.16
[INFO] [stderr]     Checking rust-core-utils v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `Write` and `self`
[INFO] [stdout]  --> src/bin/tail.rs:9:15
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::io::{self, Write};
[INFO] [stdout]   |               ^^^^  ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fmt`
[INFO] [stdout]   --> src/bin/tail.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::fmt;
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/bin/util/file.rs:18:18
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<BufRead>,
[INFO] [stdout]    |                  ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<dyn BufRead>,
[INFO] [stdout]    |                  +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/bin/util/file.rs:18:18
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<BufRead>,
[INFO] [stdout]    |                  ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<dyn BufRead>,
[INFO] [stdout]    |                  +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/bin/util/file.rs:18:18
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<BufRead>,
[INFO] [stdout]    |                  ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<dyn BufRead>,
[INFO] [stdout]    |                  +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/bin/util/file.rs:18:18
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<BufRead>,
[INFO] [stdout]    |                  ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<dyn BufRead>,
[INFO] [stdout]    |                  +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Write` and `self`
[INFO] [stdout]  --> src/bin/tail.rs:9:15
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::io::{self, Write};
[INFO] [stdout]   |               ^^^^  ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fmt`
[INFO] [stdout]   --> src/bin/tail.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 | use std::fmt;
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/bin/util/file.rs:18:18
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<BufRead>,
[INFO] [stdout]    |                  ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<dyn BufRead>,
[INFO] [stdout]    |                  +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/bin/util/file.rs:18:18
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<BufRead>,
[INFO] [stdout]    |                  ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 18 |     bufread: Box<dyn BufRead>,
[INFO] [stdout]    |                  +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `enable_escape` is never read
[INFO] [stdout]   --> src/bin/echo.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout]  7 | struct Opt {
[INFO] [stdout]    |        --- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 14 |     enable_escape: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Opt` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `enable_escape` is never read
[INFO] [stdout]   --> src/bin/echo.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout]  7 | struct Opt {
[INFO] [stdout]    |        --- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 14 |     enable_escape: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Opt` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]  --> src/bin/echo.rs:5:10
[INFO] [stdout]   |
[INFO] [stdout] 5 | #[derive(StructOpt, Debug)]
[INFO] [stdout]   |          ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout]   = note: this error originates in the derive macro `StructOpt` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]  --> src/bin/echo.rs:5:10
[INFO] [stdout]   |
[INFO] [stdout] 5 | #[derive(StructOpt, Debug)]
[INFO] [stdout]   |          ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout]   = note: this error originates in the derive macro `StructOpt` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_byte` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:14:36
[INFO] [stdout]    |
[INFO] [stdout] 14 |         let mut from_byte: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_bytes` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:15:37
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut last_bytes: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_line` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:16:36
[INFO] [stdout]    |
[INFO] [stdout] 16 |         let mut from_line: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_lines` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:17:37
[INFO] [stdout]    |
[INFO] [stdout] 17 |         let mut last_lines: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:50:31
[INFO] [stdout]    |
[INFO] [stdout] 50 |         let mut from: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:51:31
[INFO] [stdout]    |
[INFO] [stdout] 51 |         let mut last: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust-core-utils` (bin "echo" test) due to 1 previous error; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: value assigned to `from_byte` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:14:36
[INFO] [stdout]    |
[INFO] [stdout] 14 |         let mut from_byte: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_bytes` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:15:37
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut last_bytes: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_line` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:16:36
[INFO] [stdout]    |
[INFO] [stdout] 16 |         let mut from_line: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_lines` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:17:37
[INFO] [stdout]    |
[INFO] [stdout] 17 |         let mut last_lines: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:50:31
[INFO] [stdout]    |
[INFO] [stdout] 50 |         let mut from: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:51:31
[INFO] [stdout]    |
[INFO] [stdout] 51 |         let mut last: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `walk_buffer_bytes`, `walk_buffer_lines`, `last_bytes`, `last_lines`, `len`, and `buffer_position` are never used
[INFO] [stdout]    --> src/bin/util/file.rs:106:12
[INFO] [stdout]     |
[INFO] [stdout]  22 | impl FileDetail {
[INFO] [stdout]     | --------------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 106 |     pub fn walk_buffer_bytes(&mut self, bytes: usize) {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 115 |     pub fn walk_buffer_lines(&mut self, lines: usize) {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 123 |     pub fn last_bytes(&mut self, bytes: usize) -> (usize, Vec<u8>) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 142 |     pub fn last_lines(&mut self, lines: usize) -> (usize, Vec<String>) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 163 |     pub fn len(&self) -> Result<u64, io::Error> {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 177 |     pub fn buffer_position(&self) -> usize {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust-core-utils` (bin "echo") due to 1 previous error; 1 warning emitted
[INFO] [stdout] warning: enum `FileReadStrategy` is never used
[INFO] [stdout]  --> src/bin/util/file_read_strategy.rs:4:10
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub enum FileReadStrategy {
[INFO] [stdout]   |          ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated functions `pick` and `from_last_converter` are never used
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:13:12
[INFO] [stdout]    |
[INFO] [stdout] 12 | impl FileReadStrategy {
[INFO] [stdout]    | --------------------- associated functions in this implementation
[INFO] [stdout] 13 |     pub fn pick(bytes: String, lines: String) -> FileReadStrategy {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 49 |     fn from_last_converter(size: String) -> Option<(usize, usize)> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/bin/head.rs:12:10
[INFO] [stdout]    |
[INFO] [stdout] 12 | #[derive(StructOpt, Debug)]
[INFO] [stdout]    |          ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout]    = note: this error originates in the derive macro `StructOpt` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/head.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |         writter.write_all(&b.unwrap());
[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] 55 |         let _ = writter.write_all(&b.unwrap());
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust-core-utils` (bin "head") due to 1 previous error; 11 warnings emitted
[INFO] [stdout] warning: unused variable: `Nome`
[INFO] [stdout]    --> src/bin/tail.rs:196:29
[INFO] [stdout]     |
[INFO] [stdout] 196 | ...                   Nome => {
[INFO] [stdout]     |                       ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: you might have meant to pattern match on the similarly named variant `None`
[INFO] [stdout]     |
[INFO] [stdout] 196 -                             Nome => {
[INFO] [stdout] 196 +                             std::prelude::v1::None => {
[INFO] [stdout]     |
[INFO] [stdout] help: if this is intentional, prefix it with an underscore
[INFO] [stdout]     |
[INFO] [stdout] 196 |                             _Nome => {
[INFO] [stdout]     |                             +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `Nome`
[INFO] [stdout]    --> src/bin/tail.rs:241:29
[INFO] [stdout]     |
[INFO] [stdout] 241 | ...                   Nome => {
[INFO] [stdout]     |                       ^^^^
[INFO] [stdout]     |
[INFO] [stdout] help: you might have meant to pattern match on the similarly named variant `None`
[INFO] [stdout]     |
[INFO] [stdout] 241 -                             Nome => {
[INFO] [stdout] 241 +                             std::prelude::v1::None => {
[INFO] [stdout]     |
[INFO] [stdout] help: if this is intentional, prefix it with an underscore
[INFO] [stdout]     |
[INFO] [stdout] 241 |                             _Nome => {
[INFO] [stdout]     |                             +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_read` is never read
[INFO] [stdout]    --> src/bin/tail.rs:183:29
[INFO] [stdout]     |
[INFO] [stdout] 183 |         let mut last_read = 0;
[INFO] [stdout]     |                             ^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_byte` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:14:36
[INFO] [stdout]    |
[INFO] [stdout] 14 |         let mut from_byte: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_bytes` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:15:37
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut last_bytes: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_line` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:16:36
[INFO] [stdout]    |
[INFO] [stdout] 16 |         let mut from_line: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_lines` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:17:37
[INFO] [stdout]    |
[INFO] [stdout] 17 |         let mut last_lines: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:50:31
[INFO] [stdout]    |
[INFO] [stdout] 50 |         let mut from: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:51:31
[INFO] [stdout]    |
[INFO] [stdout] 51 |         let mut last: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_byte` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:14:36
[INFO] [stdout]    |
[INFO] [stdout] 14 |         let mut from_byte: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_bytes` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:15:37
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut last_bytes: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_line` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:16:36
[INFO] [stdout]    |
[INFO] [stdout] 16 |         let mut from_line: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_lines` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:17:37
[INFO] [stdout]    |
[INFO] [stdout] 17 |         let mut last_lines: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/tail.rs:296:9
[INFO] [stdout]     |
[INFO] [stdout] 296 |     let mut line_number = 0;
[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: unused variable: `line_number`
[INFO] [stdout]    --> src/bin/tail.rs:296:9
[INFO] [stdout]     |
[INFO] [stdout] 296 |     let mut line_number = 0;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_line_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `max_unchanged_stats`, `pid`, `quiet`, and `verbose` are never read
[INFO] [stdout]    --> src/bin/tail.rs:100:9
[INFO] [stdout]     |
[INFO] [stdout]  97 | struct TailOption {
[INFO] [stdout]     |        ---------- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 100 |     pub max_unchanged_stats: usize,
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 101 |     pub pid: usize,
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 102 |     pub quiet: bool,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 105 |     pub verbose: bool,
[INFO] [stdout]     |         ^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `TailOption` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `is_text`, `walk_buffer_bytes`, and `buffer_position` are never used
[INFO] [stdout]    --> src/bin/util/file.rs:102:12
[INFO] [stdout]     |
[INFO] [stdout]  22 | impl FileDetail {
[INFO] [stdout]     | --------------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 102 |     pub fn is_text(&self) -> bool {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 106 |     pub fn walk_buffer_bytes(&mut self, bytes: usize) {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 177 |     pub fn buffer_position(&self) -> usize {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:50:31
[INFO] [stdout]    |
[INFO] [stdout] 50 |         let mut from: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/bin/tail.rs:14:10
[INFO] [stdout]    |
[INFO] [stdout] 14 | #[derive(StructOpt, Debug)]
[INFO] [stdout]    |          ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout]    = note: this error originates in the derive macro `StructOpt` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:149:9
[INFO] [stdout]     |
[INFO] [stdout] 149 |         to.output_channel.send(Line{ from_file: None, content: content });
[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] 149 |         let _ = to.output_channel.send(Line{ from_file: None, content: content });
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:171:21
[INFO] [stdout]     |
[INFO] [stdout] 171 |                     to.output_channel.send(Line{ from_file: None, content: content });
[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] 171 |                     let _ = to.output_channel.send(Line{ from_file: None, content: content });
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:194:33
[INFO] [stdout]     |
[INFO] [stdout] 194 | ...                   to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[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] 194 |                                 let _ = to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `Nome` should have a snake case name
[INFO] [stdout]    --> src/bin/tail.rs:196:29
[INFO] [stdout]     |
[INFO] [stdout] 196 | ...                   Nome => {
[INFO] [stdout]     |                       ^^^^ help: convert the identifier to snake case: `nome`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_snake_case)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:212:21
[INFO] [stdout]     |
[INFO] [stdout] 212 |                     to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[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] 212 |                     let _ = to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:222:21
[INFO] [stdout]     |
[INFO] [stdout] 222 |                     to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[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] 222 |                     let _ = to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:239:33
[INFO] [stdout]     |
[INFO] [stdout] 239 | ...                   to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: b });
[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] 239 |                                 let _ = to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: b });
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `Nome` should have a snake case name
[INFO] [stdout]    --> src/bin/tail.rs:241:29
[INFO] [stdout]     |
[INFO] [stdout] 241 | ...                   Nome => {
[INFO] [stdout]     |                       ^^^^ help: convert the identifier to snake case: `nome`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:345:9
[INFO] [stdout]     |
[INFO] [stdout] 345 |         t.join();
[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] 345 |         let _ = t.join();
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:348:5
[INFO] [stdout]     |
[INFO] [stdout] 348 |     close_tx.send(true);
[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] 348 |     let _ = close_tx.send(true);
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:349:5
[INFO] [stdout]     |
[INFO] [stdout] 349 |     output_thread.join();
[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] 349 |     let _ = output_thread.join();
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:51:31
[INFO] [stdout]    |
[INFO] [stdout] 51 |         let mut last: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/cat.rs:137:17
[INFO] [stdout]     |
[INFO] [stdout] 137 |             let mut valid_line = false;
[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: unused variable: `valid_line`
[INFO] [stdout]    --> src/bin/cat.rs:137:17
[INFO] [stdout]     |
[INFO] [stdout] 137 |             let mut valid_line = false;
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_valid_line`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `blank_line_count`
[INFO] [stdout]    --> src/bin/cat.rs:143:30
[INFO] [stdout]     |
[INFO] [stdout] 143 |             let (valid_line, blank_line_count) = valid(line.clone(), blank_line_count, opt.squeeze_blank);
[INFO] [stdout]     |                              ^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_blank_line_count`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `number_nonempty` and `ignored` are never read
[INFO] [stdout]   --> src/bin/cat.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 14 | struct Opt {
[INFO] [stdout]    |        --- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 21 |     number_nonempty: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 49 |     ignored: bool,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Opt` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `walk_buffer_bytes`, `walk_buffer_lines`, `last_bytes`, `last_lines`, `len`, and `buffer_position` are never used
[INFO] [stdout]    --> src/bin/util/file.rs:106:12
[INFO] [stdout]     |
[INFO] [stdout]  22 | impl FileDetail {
[INFO] [stdout]     | --------------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 106 |     pub fn walk_buffer_bytes(&mut self, bytes: usize) {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 115 |     pub fn walk_buffer_lines(&mut self, lines: usize) {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 123 |     pub fn last_bytes(&mut self, bytes: usize) -> (usize, Vec<u8>) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 142 |     pub fn last_lines(&mut self, lines: usize) -> (usize, Vec<String>) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 163 |     pub fn len(&self) -> Result<u64, io::Error> {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 177 |     pub fn buffer_position(&self) -> usize {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `FileReadStrategy` is never used
[INFO] [stdout]  --> src/bin/util/file_read_strategy.rs:4:10
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub enum FileReadStrategy {
[INFO] [stdout]   |          ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated functions `pick` and `from_last_converter` are never used
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:13:12
[INFO] [stdout]    |
[INFO] [stdout] 12 | impl FileReadStrategy {
[INFO] [stdout]    | --------------------- associated functions in this implementation
[INFO] [stdout] 13 |     pub fn pick(bytes: String, lines: String) -> FileReadStrategy {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 49 |     fn from_last_converter(size: String) -> Option<(usize, usize)> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_byte` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:14:36
[INFO] [stdout]    |
[INFO] [stdout] 14 |         let mut from_byte: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_bytes` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:15:37
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut last_bytes: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_line` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:16:36
[INFO] [stdout]    |
[INFO] [stdout] 16 |         let mut from_line: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_lines` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:17:37
[INFO] [stdout]    |
[INFO] [stdout] 17 |         let mut last_lines: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:50:31
[INFO] [stdout]    |
[INFO] [stdout] 50 |         let mut from: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:51:31
[INFO] [stdout]    |
[INFO] [stdout] 51 |         let mut last: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/cat.rs:137:17
[INFO] [stdout]     |
[INFO] [stdout] 137 |             let mut valid_line = false;
[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: unused variable: `valid_line`
[INFO] [stdout]    --> src/bin/cat.rs:137:17
[INFO] [stdout]     |
[INFO] [stdout] 137 |             let mut valid_line = false;
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_valid_line`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `blank_line_count`
[INFO] [stdout]    --> src/bin/cat.rs:143:30
[INFO] [stdout]     |
[INFO] [stdout] 143 |             let (valid_line, blank_line_count) = valid(line.clone(), blank_line_count, opt.squeeze_blank);
[INFO] [stdout]     |                              ^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_blank_line_count`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `number_nonempty` and `ignored` are never read
[INFO] [stdout]   --> src/bin/cat.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 14 | struct Opt {
[INFO] [stdout]    |        --- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 21 |     number_nonempty: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 49 |     ignored: bool,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Opt` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `walk_buffer_bytes`, `walk_buffer_lines`, `last_bytes`, `last_lines`, `len`, and `buffer_position` are never used
[INFO] [stdout]    --> src/bin/util/file.rs:106:12
[INFO] [stdout]     |
[INFO] [stdout]  22 | impl FileDetail {
[INFO] [stdout]     | --------------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 106 |     pub fn walk_buffer_bytes(&mut self, bytes: usize) {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 115 |     pub fn walk_buffer_lines(&mut self, lines: usize) {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 123 |     pub fn last_bytes(&mut self, bytes: usize) -> (usize, Vec<u8>) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 142 |     pub fn last_lines(&mut self, lines: usize) -> (usize, Vec<String>) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 163 |     pub fn len(&self) -> Result<u64, io::Error> {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 177 |     pub fn buffer_position(&self) -> usize {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `FileReadStrategy` is never used
[INFO] [stdout]  --> src/bin/util/file_read_strategy.rs:4:10
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub enum FileReadStrategy {
[INFO] [stdout]   |          ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated functions `pick` and `from_last_converter` are never used
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:13:12
[INFO] [stdout]    |
[INFO] [stdout] 12 | impl FileReadStrategy {
[INFO] [stdout]    | --------------------- associated functions in this implementation
[INFO] [stdout] 13 |     pub fn pick(bytes: String, lines: String) -> FileReadStrategy {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 49 |     fn from_last_converter(size: String) -> Option<(usize, usize)> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/bin/cat.rs:12:10
[INFO] [stdout]    |
[INFO] [stdout] 12 | #[derive(StructOpt, Debug)]
[INFO] [stdout]    |          ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout]    = note: this error originates in the derive macro `StructOpt` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/cat.rs:153:13
[INFO] [stdout]     |
[INFO] [stdout] 153 | /             match f.read_chunk(size) {
[INFO] [stdout] 154 | |                 Some(b) => writter.write_all(&b),
[INFO] [stdout] 155 | |                 _ => Ok(()),
[INFO] [stdout] 156 | |             };
[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] 153 |             let _ = match f.read_chunk(size) {
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust-core-utils` (bin "tail") due to 1 previous error; 27 warnings emitted
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/bin/cat.rs:12:10
[INFO] [stdout]    |
[INFO] [stdout] 12 | #[derive(StructOpt, Debug)]
[INFO] [stdout]    |          ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout]    = note: this error originates in the derive macro `StructOpt` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/cat.rs:153:13
[INFO] [stdout]     |
[INFO] [stdout] 153 | /             match f.read_chunk(size) {
[INFO] [stdout] 154 | |                 Some(b) => writter.write_all(&b),
[INFO] [stdout] 155 | |                 _ => Ok(()),
[INFO] [stdout] 156 | |             };
[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] 153 |             let _ = match f.read_chunk(size) {
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_byte` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:14:36
[INFO] [stdout]    |
[INFO] [stdout] 14 |         let mut from_byte: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_bytes` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:15:37
[INFO] [stdout]    |
[INFO] [stdout] 15 |         let mut last_bytes: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from_line` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:16:36
[INFO] [stdout]    |
[INFO] [stdout] 16 |         let mut from_line: usize = 0;
[INFO] [stdout]    |                                    ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_lines` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:17:37
[INFO] [stdout]    |
[INFO] [stdout] 17 |         let mut last_lines: usize = 0;
[INFO] [stdout]    |                                     ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `walk_buffer_bytes`, `walk_buffer_lines`, `last_bytes`, `last_lines`, `len`, and `buffer_position` are never used
[INFO] [stdout]    --> src/bin/util/file.rs:106:12
[INFO] [stdout]     |
[INFO] [stdout]  22 | impl FileDetail {
[INFO] [stdout]     | --------------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 106 |     pub fn walk_buffer_bytes(&mut self, bytes: usize) {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 115 |     pub fn walk_buffer_lines(&mut self, lines: usize) {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 123 |     pub fn last_bytes(&mut self, bytes: usize) -> (usize, Vec<u8>) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 142 |     pub fn last_lines(&mut self, lines: usize) -> (usize, Vec<String>) {
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 163 |     pub fn len(&self) -> Result<u64, io::Error> {
[INFO] [stdout]     |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 177 |     pub fn buffer_position(&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: enum `FileReadStrategy` is never used
[INFO] [stdout]  --> src/bin/util/file_read_strategy.rs:4:10
[INFO] [stdout]   |
[INFO] [stdout] 4 | pub enum FileReadStrategy {
[INFO] [stdout]   |          ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `from` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:50:31
[INFO] [stdout]    |
[INFO] [stdout] 50 |         let mut from: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated functions `pick` and `from_last_converter` are never used
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:13:12
[INFO] [stdout]    |
[INFO] [stdout] 12 | impl FileReadStrategy {
[INFO] [stdout]    | --------------------- associated functions in this implementation
[INFO] [stdout] 13 |     pub fn pick(bytes: String, lines: String) -> FileReadStrategy {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 49 |     fn from_last_converter(size: String) -> Option<(usize, usize)> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last` is never read
[INFO] [stdout]   --> src/bin/util/file_read_strategy.rs:51:31
[INFO] [stdout]    |
[INFO] [stdout] 51 |         let mut last: usize = 0;
[INFO] [stdout]    |                               ^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/bin/head.rs:12:10
[INFO] [stdout]    |
[INFO] [stdout] 12 | #[derive(StructOpt, Debug)]
[INFO] [stdout]    |          ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout]    = note: this error originates in the derive macro `StructOpt` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/head.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |         writter.write_all(&b.unwrap());
[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] 55 |         let _ = writter.write_all(&b.unwrap());
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust-core-utils` (bin "cat" test) due to 1 previous error; 15 warnings emitted
[INFO] [stderr] error: could not compile `rust-core-utils` (bin "head" test) due to 1 previous error; 11 warnings emitted
[INFO] [stderr] error: could not compile `rust-core-utils` (bin "cat") due to 1 previous error; 15 warnings emitted
[INFO] [stdout] warning: unused variable: `Nome`
[INFO] [stdout]    --> src/bin/tail.rs:196:29
[INFO] [stdout]     |
[INFO] [stdout] 196 | ...                   Nome => {
[INFO] [stdout]     |                       ^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: you might have meant to pattern match on the similarly named variant `None`
[INFO] [stdout]     |
[INFO] [stdout] 196 -                             Nome => {
[INFO] [stdout] 196 +                             std::prelude::v1::None => {
[INFO] [stdout]     |
[INFO] [stdout] help: if this is intentional, prefix it with an underscore
[INFO] [stdout]     |
[INFO] [stdout] 196 |                             _Nome => {
[INFO] [stdout]     |                             +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `Nome`
[INFO] [stdout]    --> src/bin/tail.rs:241:29
[INFO] [stdout]     |
[INFO] [stdout] 241 | ...                   Nome => {
[INFO] [stdout]     |                       ^^^^
[INFO] [stdout]     |
[INFO] [stdout] help: you might have meant to pattern match on the similarly named variant `None`
[INFO] [stdout]     |
[INFO] [stdout] 241 -                             Nome => {
[INFO] [stdout] 241 +                             std::prelude::v1::None => {
[INFO] [stdout]     |
[INFO] [stdout] help: if this is intentional, prefix it with an underscore
[INFO] [stdout]     |
[INFO] [stdout] 241 |                             _Nome => {
[INFO] [stdout]     |                             +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `last_read` is never read
[INFO] [stdout]    --> src/bin/tail.rs:183:29
[INFO] [stdout]     |
[INFO] [stdout] 183 |         let mut last_read = 0;
[INFO] [stdout]     |                             ^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/tail.rs:296:9
[INFO] [stdout]     |
[INFO] [stdout] 296 |     let mut line_number = 0;
[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: unused variable: `line_number`
[INFO] [stdout]    --> src/bin/tail.rs:296:9
[INFO] [stdout]     |
[INFO] [stdout] 296 |     let mut line_number = 0;
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_line_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `max_unchanged_stats`, `pid`, `quiet`, and `verbose` are never read
[INFO] [stdout]    --> src/bin/tail.rs:100:9
[INFO] [stdout]     |
[INFO] [stdout]  97 | struct TailOption {
[INFO] [stdout]     |        ---------- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 100 |     pub max_unchanged_stats: usize,
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 101 |     pub pid: usize,
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 102 |     pub quiet: bool,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 105 |     pub verbose: bool,
[INFO] [stdout]     |         ^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `TailOption` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]     = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: methods `is_text`, `walk_buffer_bytes`, and `buffer_position` are never used
[INFO] [stdout]    --> src/bin/util/file.rs:102:12
[INFO] [stdout]     |
[INFO] [stdout]  22 | impl FileDetail {
[INFO] [stdout]     | --------------- methods in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 102 |     pub fn is_text(&self) -> bool {
[INFO] [stdout]     |            ^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 106 |     pub fn walk_buffer_bytes(&mut self, bytes: usize) {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 177 |     pub fn buffer_position(&self) -> usize {
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/bin/tail.rs:14:10
[INFO] [stdout]    |
[INFO] [stdout] 14 | #[derive(StructOpt, Debug)]
[INFO] [stdout]    |          ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout]    = note: this error originates in the derive macro `StructOpt` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:149:9
[INFO] [stdout]     |
[INFO] [stdout] 149 |         to.output_channel.send(Line{ from_file: None, content: content });
[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] 149 |         let _ = to.output_channel.send(Line{ from_file: None, content: content });
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:171:21
[INFO] [stdout]     |
[INFO] [stdout] 171 |                     to.output_channel.send(Line{ from_file: None, content: content });
[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] 171 |                     let _ = to.output_channel.send(Line{ from_file: None, content: content });
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:194:33
[INFO] [stdout]     |
[INFO] [stdout] 194 | ...                   to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[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] 194 |                                 let _ = to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `Nome` should have a snake case name
[INFO] [stdout]    --> src/bin/tail.rs:196:29
[INFO] [stdout]     |
[INFO] [stdout] 196 | ...                   Nome => {
[INFO] [stdout]     |                       ^^^^ help: convert the identifier to snake case: `nome`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_snake_case)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:212:21
[INFO] [stdout]     |
[INFO] [stdout] 212 |                     to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[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] 212 |                     let _ = to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:222:21
[INFO] [stdout]     |
[INFO] [stdout] 222 |                     to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[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] 222 |                     let _ = to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: content });
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:239:33
[INFO] [stdout]     |
[INFO] [stdout] 239 | ...                   to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: b });
[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] 239 |                                 let _ = to.output_channel.send(Line{ from_file: Some(to.file.clone()), content: b });
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `Nome` should have a snake case name
[INFO] [stdout]    --> src/bin/tail.rs:241:29
[INFO] [stdout]     |
[INFO] [stdout] 241 | ...                   Nome => {
[INFO] [stdout]     |                       ^^^^ help: convert the identifier to snake case: `nome`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:345:9
[INFO] [stdout]     |
[INFO] [stdout] 345 |         t.join();
[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] 345 |         let _ = t.join();
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:348:5
[INFO] [stdout]     |
[INFO] [stdout] 348 |     close_tx.send(true);
[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] 348 |     let _ = close_tx.send(true);
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/bin/tail.rs:349:5
[INFO] [stdout]     |
[INFO] [stdout] 349 |     output_thread.join();
[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] 349 |     let _ = output_thread.join();
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust-core-utils` (bin "tail" test) due to 1 previous error; 27 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "6a47968f69ea48fc0ab0843a211bec686ce3ee19fb48d3c3eb025556a2a1a53d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6a47968f69ea48fc0ab0843a211bec686ce3ee19fb48d3c3eb025556a2a1a53d", kill_on_drop: false }`
[INFO] [stdout] 6a47968f69ea48fc0ab0843a211bec686ce3ee19fb48d3c3eb025556a2a1a53d
