[INFO] cloning repository https://github.com/zachlefevre/rust-learning
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/zachlefevre/rust-learning" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzachlefevre%2Frust-learning", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzachlefevre%2Frust-learning'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6e8771639450277fa7f86da2484b047b58836690
[INFO] testing zachlefevre/rust-learning against master#c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38 for pr-146098-7
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fzachlefevre%2Frust-learning" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/zachlefevre/rust-learning
[INFO] finished tweaking git repo https://github.com/zachlefevre/rust-learning
[INFO] tweaked toml for git repo https://github.com/zachlefevre/rust-learning written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/zachlefevre/rust-learning on toolchain c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/zachlefevre/rust-learning already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded cc v1.0.104
[INFO] [stderr]   Downloaded syn v2.0.68
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c10003fe3e2d7bd49a4c520335a2fc23a31749588ac248ee732193d0247a1847
[INFO] running `Command { std: "docker" "start" "-a" "c10003fe3e2d7bd49a4c520335a2fc23a31749588ac248ee732193d0247a1847", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c10003fe3e2d7bd49a4c520335a2fc23a31749588ac248ee732193d0247a1847", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c10003fe3e2d7bd49a4c520335a2fc23a31749588ac248ee732193d0247a1847", kill_on_drop: false }`
[INFO] [stdout] c10003fe3e2d7bd49a4c520335a2fc23a31749588ac248ee732193d0247a1847
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 39f27f42e7b22aa8792492ae93c6124265544fc7228bf8284bbb2a9a50459f48
[INFO] running `Command { std: "docker" "start" "-a" "39f27f42e7b22aa8792492ae93c6124265544fc7228bf8284bbb2a9a50459f48", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.155
[INFO] [stderr]    Compiling proc-macro2 v1.0.86
[INFO] [stderr]    Compiling autocfg v1.3.0
[INFO] [stderr]    Compiling ppv-lite86 v0.2.17
[INFO] [stderr]    Compiling serde v1.0.203
[INFO] [stderr]    Compiling pin-project-lite v0.2.14
[INFO] [stderr]    Compiling bytes v1.6.0
[INFO] [stderr]    Compiling lock_api v0.4.12
[INFO] [stderr]    Compiling quote v1.0.36
[INFO] [stderr]    Compiling syn v2.0.68
[INFO] [stderr]    Compiling getrandom v0.2.15
[INFO] [stderr]    Compiling parking_lot_core v0.9.10
[INFO] [stderr]    Compiling signal-hook-registry v1.4.2
[INFO] [stderr]    Compiling num_cpus v1.16.0
[INFO] [stderr]    Compiling socket2 v0.5.7
[INFO] [stderr]    Compiling mio v0.8.11
[INFO] [stderr]    Compiling rand_core v0.6.4
[INFO] [stderr]    Compiling parking_lot v0.12.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.5
[INFO] [stderr]    Compiling serde_derive v1.0.203
[INFO] [stderr]    Compiling tokio-macros v2.3.0
[INFO] [stderr]    Compiling tokio v1.38.0
[INFO] [stderr]    Compiling practice v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `ffi::OsString`
[INFO] [stdout]  --> src/bin/paths.rs:1:16
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{env, ffi::OsString, path::{Path, PathBuf}};
[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 variable: `p`
[INFO] [stdout]  --> src/bin/paths.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn foo(p: PathBuf) {
[INFO] [stdout]   |        ^ help: if this is intentional, prefix it with an underscore: `_p`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]  --> src/bin/destructuring.rs:4:10
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let (ref a, b) = *t;
[INFO] [stdout]   |          ^^^^^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]  --> src/bin/destructuring.rs:4:17
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let (ref a, b) = *t;
[INFO] [stdout]   |                 ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/bin/destructuring.rs:12:10
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let (ref a, b) = t;
[INFO] [stdout]    |          ^^^^^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/bin/destructuring.rs:12:17
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let (ref a, b) = t;
[INFO] [stdout]    |                 ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `one` is never used
[INFO] [stdout]  --> src/bin/destructuring.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn one() {
[INFO] [stdout]   |    ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `two` is never used
[INFO] [stdout]  --> src/bin/destructuring.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn two() {
[INFO] [stdout]   |    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `home`
[INFO] [stdout]  --> src/bin/paths.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let home = env::home_dir();
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_home`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `foo` is never used
[INFO] [stdout]  --> src/bin/paths.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn foo(p: PathBuf) {
[INFO] [stdout]   |    ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/bin/strings.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let s1 = String::from(s);
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/bin/strings.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let s2 = s.to_owned();
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Write`
[INFO] [stdout]  --> src/bin/vec_fns.rs:1:41
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::io::{BufReader, self, BufRead, Write, Read};
[INFO] [stdout]   |                                         ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/vec_fns.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let mut file = std::fs::File::open("vec_fns.rs").unwrap();
[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/bin/vec_fns.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let mut s = String::new();
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/vec_fns.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let mut s = String::new();
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` in tuple element 0 that must be used
[INFO] [stdout]   --> src/bin/join.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     dbg!(tokio::join!(tokio::spawn(a), tokio::spawn(b), tokio::spawn(c)));
[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] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` in tuple element 1 that must be used
[INFO] [stdout]   --> src/bin/join.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     dbg!(tokio::join!(tokio::spawn(a), tokio::spawn(b), tokio::spawn(c)));
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` in tuple element 2 that must be used
[INFO] [stdout]   --> src/bin/join.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     dbg!(tokio::join!(tokio::spawn(a), tokio::spawn(b), tokio::spawn(c)));
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/vec_fns.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     bufreader.read_until(b'B', &mut v);
[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] 14 |     let _ = bufreader.read_until(b'B', &mut v);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/vec_fns.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 |     dbg!(String::from_utf8(v));
[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] 17 |     let _ = dbg!(String::from_utf8(v));
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/vec_fns.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 |     io::copy(&mut bufreader, &mut io::stderr());
[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] 19 |     let _ = io::copy(&mut bufreader, &mut io::stderr());
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]  --> src/bin/index.rs:8:21
[INFO] [stdout]   |
[INFO] [stdout] 8 |     fn index(&self, i: f32) -> &Self:: Output {
[INFO] [stdout]   |                     ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `value`
[INFO] [stdout]  --> src/bin/options.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let value = op.unwrap_or(18);
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_value`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `value`
[INFO] [stdout]  --> src/bin/options.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let value = op.unwrap_or("hey there".to_string());
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_value`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/pinning.rs:16:13
[INFO] [stdout]    |
[INFO] [stdout] 16 |         let t: Pin<&Foo> = thing(Pin::new_unchecked(&Foo::new()));
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: multiple patterns overlap on their endpoints
[INFO] [stdout]  --> src/bin/matches.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |         0..=8 => "true",
[INFO] [stdout]   |         ----- this range overlaps on `8_i32`...
[INFO] [stdout] 4 |         8..=18 => "true again",
[INFO] [stdout]   |         ^^^^^^ ... with this range
[INFO] [stdout]   |
[INFO] [stdout]   = note: you likely meant to write mutually exclusive ranges
[INFO] [stdout]   = note: `#[warn(overlapping_range_endpoints)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0004]: non-exhaustive patterns: `i32::MIN..=-1_i32` and `19_i32..=i32::MAX` not covered
[INFO] [stdout]  --> src/bin/matches.rs:2:19
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let v = match 2 {
[INFO] [stdout]   |                   ^ patterns `i32::MIN..=-1_i32` and `19_i32..=i32::MAX` not covered
[INFO] [stdout]   |
[INFO] [stdout]   = note: the matched value is of type `i32`
[INFO] [stdout] help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern, a match arm with multiple or-patterns as shown, or multiple match arms
[INFO] [stdout]   |
[INFO] [stdout] 4 ~         8..=18 => "true again",
[INFO] [stdout] 5 ~         i32::MIN..=-1_i32 | 19_i32..=i32::MAX => todo!(),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0004`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `practice` (bin "matches") due to 1 previous error; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]  --> src/bin/choose_weighted.rs:5:4
[INFO] [stdout]   |
[INFO] [stdout] 5 |    dbg!(v.choose_weighted(&mut rand::thread_rng(), |x| *x));
[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] 5 |    let _ = dbg!(v.choose_weighted(&mut rand::thread_rng(), |x| *x));
[INFO] [stdout]   |    +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the trait bound `[_; 0]: std::io::Read` is not satisfied
[INFO] [stdout]  --> src/bin/bufread_test.rs:7:37
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let mut reader = BufReader::new(input);
[INFO] [stdout]   |                      -------------- ^^^^^ the trait `std::io::Read` is not implemented for `[_; 0]`
[INFO] [stdout]   |                      |
[INFO] [stdout]   |                      required by a bound introduced by this call
[INFO] [stdout]   |
[INFO] [stdout] help: the trait `std::io::Read` is implemented for `&[u8]`
[INFO] [stdout]  --> /rustc/c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38/library/std/src/io/impls.rs:298:0
[INFO] [stdout] note: required by a bound in `BufReader::<R>::new`
[INFO] [stdout]  --> /rustc/c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38/library/std/src/io/buffered/bufreader.rs:73:4
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: the method `read_line` exists for struct `BufReader<[_; 0]>`, but its trait bounds were not satisfied
[INFO] [stdout]   --> src/bin/bufread_test.rs:13:26
[INFO] [stdout]    |
[INFO] [stdout] 13 |     while let _ = reader.read_line(&mut buf).unwrap() {
[INFO] [stdout]    |                          ^^^^^^^^^ method cannot be called on `BufReader<[_; 0]>` due to unsatisfied trait bounds
[INFO] [stdout]    |
[INFO] [stdout]    = note: the following trait bounds were not satisfied:
[INFO] [stdout]            `[_; 0]: std::io::Read`
[INFO] [stdout]            which is required by `BufReader<[_; 0]>: BufRead`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0277, E0599.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `practice` (bin "bufread_test") due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "39f27f42e7b22aa8792492ae93c6124265544fc7228bf8284bbb2a9a50459f48", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "39f27f42e7b22aa8792492ae93c6124265544fc7228bf8284bbb2a9a50459f48", kill_on_drop: false }`
[INFO] [stdout] 39f27f42e7b22aa8792492ae93c6124265544fc7228bf8284bbb2a9a50459f48