[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 try#c2e32f1c9652b13ed99608599c1e855462f421f3 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-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/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-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/zachlefevre/rust-learning on toolchain c2e32f1c9652b13ed99608599c1e855462f421f3
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "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" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 675222c04a3e7d4b0117d03d50eeb4723bc84e08bfb95a0156b7a477ef22c109
[INFO] running `Command { std: "docker" "start" "-a" "675222c04a3e7d4b0117d03d50eeb4723bc84e08bfb95a0156b7a477ef22c109", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "675222c04a3e7d4b0117d03d50eeb4723bc84e08bfb95a0156b7a477ef22c109", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "675222c04a3e7d4b0117d03d50eeb4723bc84e08bfb95a0156b7a477ef22c109", kill_on_drop: false }`
[INFO] [stdout] 675222c04a3e7d4b0117d03d50eeb4723bc84e08bfb95a0156b7a477ef22c109
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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" "-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" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b89e0f5fd90a1c370f593ddf15a1b65fc9e827c746197fb962fd586c14fde44b
[INFO] running `Command { std: "docker" "start" "-a" "b89e0f5fd90a1c370f593ddf15a1b65fc9e827c746197fb962fd586c14fde44b", 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 getrandom v0.2.15
[INFO] [stderr]    Compiling parking_lot_core v0.9.10
[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 signal-hook-registry v1.4.2
[INFO] [stderr]    Compiling quote v1.0.36
[INFO] [stderr]    Compiling parking_lot v0.12.3
[INFO] [stderr]    Compiling syn v2.0.68
[INFO] [stderr]    Compiling rand_core v0.6.4
[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: struct `Bar` is never constructed
[INFO] [stdout]   --> src/bin/oop.rs:12:8
[INFO] [stdout]    |
[INFO] [stdout] 12 | struct Bar;
[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: `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] 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/c2e32f1c9652b13ed99608599c1e855462f421f3/library/std/src/io/impls.rs:298:0
[INFO] [stdout] note: required by a bound in `BufReader::<R>::new`
[INFO] [stdout]  --> /rustc/c2e32f1c9652b13ed99608599c1e855462f421f3/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] warning: unused variable: `v`
[INFO] [stdout]   --> src/bin/mutx.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let v = m.lock();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `data` is never read
[INFO] [stdout]  --> src/bin/mutx.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct MtxGuard<'a, T> {
[INFO] [stdout]   |        -------- field in this struct
[INFO] [stdout] 6 |     data: &'a T
[INFO] [stdout]   |     ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/bin/mutx.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn lock(&self) -> MtxGuard<T> {
[INFO] [stdout]    |             ^^^^^     ^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |             |
[INFO] [stdout]    |             the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn lock(&self) -> MtxGuard<'_, T> {
[INFO] [stdout]    |                                +++
[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] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/bin/select-most-recent.rs:7:14
[INFO] [stdout]   |
[INFO] [stdout] 7 |         Some(v) => Some("foo".into())
[INFO] [stdout]   |              ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `practice` (bin "bufread_test") due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/typeclasses.rs:62:17
[INFO] [stdout]    |
[INFO] [stdout] 62 |             let s = ai.0;
[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: struct `FileDownloadRequest` is never constructed
[INFO] [stdout]   --> src/bin/typeclasses.rs:54:12
[INFO] [stdout]    |
[INFO] [stdout] 54 |     struct FileDownloadRequest<P: protocol::Protocol> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `mount_point` is never used
[INFO] [stdout]   --> src/bin/typeclasses.rs:59:12
[INFO] [stdout]    |
[INFO] [stdout] 58 |     impl FileDownloadRequest<protocol::Nfs> {
[INFO] [stdout]    |     --------------------------------------- method in this implementation
[INFO] [stdout] 59 |         fn mount_point(&self) -> &String {
[INFO] [stdout]    |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `other` is never used
[INFO] [stdout]   --> src/bin/typeclasses.rs:68:12
[INFO] [stdout]    |
[INFO] [stdout] 67 |     impl FileDownloadRequest<protocol::Bootp> {
[INFO] [stdout]    |     ----------------------------------------- method in this implementation
[INFO] [stdout] 68 |         fn other(&self) -> i32 {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `AuthInfo` is never constructed
[INFO] [stdout]  --> src/bin/typeclasses.rs:6:20
[INFO] [stdout]   |
[INFO] [stdout] 6 |         pub struct AuthInfo(pub String);
[INFO] [stdout]   |                    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `AuthInfo` is never constructed
[INFO] [stdout]   --> src/bin/typeclasses.rs:10:20
[INFO] [stdout]    |
[INFO] [stdout] 10 |         pub struct AuthInfo(pub i32);
[INFO] [stdout]    |                    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `TransferParameters` is never constructed
[INFO] [stdout]   --> src/bin/typeclasses.rs:17:20
[INFO] [stdout]    |
[INFO] [stdout] 17 |         pub struct TransferParameters {
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Protocol` is never used
[INFO] [stdout]   --> src/bin/typeclasses.rs:22:19
[INFO] [stdout]    |
[INFO] [stdout] 22 |         pub trait Protocol {
[INFO] [stdout]    |                   ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Nfs` is never constructed
[INFO] [stdout]   --> src/bin/typeclasses.rs:28:20
[INFO] [stdout]    |
[INFO] [stdout] 28 |         pub struct Nfs {
[INFO] [stdout]    |                    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Bootp` is never constructed
[INFO] [stdout]   --> src/bin/typeclasses.rs:41:20
[INFO] [stdout]    |
[INFO] [stdout] 41 |         pub struct Bootp;
[INFO] [stdout]    |                    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `buf`
[INFO] [stdout]  --> src/bin/io.rs:5:24
[INFO] [stdout]   |
[INFO] [stdout] 5 |     fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
[INFO] [stdout]   |                        ^^^ help: if this is intentional, prefix it with an underscore: `_buf`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `buf`
[INFO] [stdout]   --> src/bin/io.rs:11:25
[INFO] [stdout]    |
[INFO] [stdout] 11 |     fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
[INFO] [stdout]    |                         ^^^ help: if this is intentional, prefix it with an underscore: `_buf`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `amt`
[INFO] [stdout]   --> src/bin/io.rs:25:27
[INFO] [stdout]    |
[INFO] [stdout] 25 |     fn consume(&mut self, amt: usize) {
[INFO] [stdout]    |                           ^^^ help: if this is intentional, prefix it with an underscore: `_amt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `n`
[INFO] [stdout]   --> src/bin/io.rs:31:8
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn foo(n: &dyn BufRead) {
[INFO] [stdout]    |        ^ help: if this is intentional, prefix it with an underscore: `_n`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `writer`
[INFO] [stdout]   --> src/bin/io.rs:47:9
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let writer = BufWriter::new(file);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_writer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Foo` is never constructed
[INFO] [stdout]  --> src/bin/io.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Foo;
[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 `foo` is never used
[INFO] [stdout]   --> src/bin/io.rs:31:4
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn foo(n: &dyn BufRead) {
[INFO] [stdout]    |    ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `smallest` is never used
[INFO] [stdout]  --> src/bin/k-smallest.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn smallest(items: impl Iterator<Item = i32>, k: u32) -> Vec<i32> {
[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 `Result` that must be used
[INFO] [stdout]   --> src/bin/io.rs:44:5
[INFO] [stdout]    |
[INFO] [stdout] 44 |     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]    = 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] 44 |     let _ = dbg!(String::from_utf8(v));
[INFO] [stdout]    |     +++++++
[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 variable: `a`
[INFO] [stdout]  --> src/bin/atomics.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let a = AtomicBool::new(true);
[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: variant `EnglishClass` is never constructed
[INFO] [stdout]   --> src/bin/folder.rs:10:5
[INFO] [stdout]    |
[INFO] [stdout]  8 | enum Classroom {
[INFO] [stdout]    |      --------- variant in this enum
[INFO] [stdout]  9 |     ScienceLab { num_beakers: i32, eyewash: bool},
[INFO] [stdout] 10 |     EnglishClass { num_books: i32 }
[INFO] [stdout]    |     ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Classroom` has derived impls for the traits `Debug` and `Clone`, but these are intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "b89e0f5fd90a1c370f593ddf15a1b65fc9e827c746197fb962fd586c14fde44b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b89e0f5fd90a1c370f593ddf15a1b65fc9e827c746197fb962fd586c14fde44b", kill_on_drop: false }`
[INFO] [stdout] b89e0f5fd90a1c370f593ddf15a1b65fc9e827c746197fb962fd586c14fde44b