[INFO] cloning repository https://github.com/olegfomenko/learn-rust-2
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/olegfomenko/learn-rust-2" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Folegfomenko%2Flearn-rust-2", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Folegfomenko%2Flearn-rust-2'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0b16b0be958e9d6b8400a6ad2eb64ee3e5a7c00e
[INFO] checking olegfomenko/learn-rust-2 against beta-2021-10-15 for beta-1.56-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Folegfomenko%2Flearn-rust-2" "/workspace/builds/worker-11/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/olegfomenko/learn-rust-2 on toolchain beta-2021-10-15
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-10-15" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/olegfomenko/learn-rust-2
[INFO] finished tweaking git repo https://github.com/olegfomenko/learn-rust-2
[INFO] tweaked toml for git repo https://github.com/olegfomenko/learn-rust-2 written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/olegfomenko/learn-rust-2 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-10-15" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-10-15" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] dee1e6fb9fd617cd2776f527bb566d3f31468a971efaafd3c1b43fac33d5304e
[INFO] running `Command { std: "docker" "start" "-a" "dee1e6fb9fd617cd2776f527bb566d3f31468a971efaafd3c1b43fac33d5304e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dee1e6fb9fd617cd2776f527bb566d3f31468a971efaafd3c1b43fac33d5304e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dee1e6fb9fd617cd2776f527bb566d3f31468a971efaafd3c1b43fac33d5304e", kill_on_drop: false }`
[INFO] [stdout] dee1e6fb9fd617cd2776f527bb566d3f31468a971efaafd3c1b43fac33d5304e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-10-15" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a5ebdc75cfb4339b70cc9ce61426e312b73087f3ece7f21b5482ed04ee0e97ea
[INFO] running `Command { std: "docker" "start" "-a" "a5ebdc75cfb4339b70cc9ce61426e312b73087f3ece7f21b5482ed04ee0e97ea", kill_on_drop: false }`
[INFO] [stderr]     Checking rust-2 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking closures v0.1.0 (/opt/rustwide/workdir/closures)
[INFO] [stderr]     Checking lifetime v0.1.0 (/opt/rustwide/workdir/lifetime)
[INFO] [stderr]     Checking slices v0.1.0 (/opt/rustwide/workdir/slices)
[INFO] [stderr]     Checking enums v0.1.0 (/opt/rustwide/workdir/enums)
[INFO] [stderr]     Checking generics v0.1.0 (/opt/rustwide/workdir/generics)
[INFO] [stderr]     Checking collections v0.1.0 (/opt/rustwide/workdir/collections)
[INFO] [stderr]     Checking references v0.1.0 (/opt/rustwide/workdir/references)
[INFO] [stderr]     Checking exceptions v0.1.0 (/opt/rustwide/workdir/exceptions)
[INFO] [stderr]     Checking structs v0.1.0 (/opt/rustwide/workdir/structs)
[INFO] [stdout] warning: variable `alive` is assigned to, but never used
[INFO] [stdout]   --> lifetime/src/main.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let alive;
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout]    = note: consider using `_alive` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `alive` is never read
[INFO] [stdout]   --> lifetime/src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |         alive = AliveStructure {
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> lifetime/src/main.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let s: &'static str = "I have a static lifetime.";
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `longest_with_an_announcement`
[INFO] [stdout]   --> lifetime/src/main.rs:55:4
[INFO] [stdout]    |
[INFO] [stdout] 55 | fn longest_with_an_announcement<'a, T>(x: &'a str, y: &'a str, ann: T) -> &'a str
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> generics/src/main.rs:50:73
[INFO] [stdout]    |
[INFO] [stdout] 50 | fn some_function<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) -> i32 {}
[INFO] [stdout]    |    -------------                                                        ^^^ expected `i32`, found `()`
[INFO] [stdout]    |    |
[INFO] [stdout]    |    implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> generics/src/main.rs:52:52
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn some_function_refactored<T, U>(t: &T, u: &U) -> i32
[INFO] [stdout]    |    ------------------------                        ^^^ expected `i32`, found `()`
[INFO] [stdout]    |    |
[INFO] [stdout]    |    implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]  --> slices/src/main.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let hello = &s[0..5];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]  --> slices/src/main.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let world = &s[6..11];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> slices/src/main.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let slice = &a[1..3];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `country`
[INFO] [stdout]   --> enums/src/main.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let country = Countries::UKRAINE;
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_country`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `country`
[INFO] [stdout]   --> enums/src/main.rs:58:11
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn travel(country: Countries) {}
[INFO] [stdout]    |           ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_country`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ip`
[INFO] [stdout]   --> enums/src/main.rs:60:10
[INFO] [stdout]    |
[INFO] [stdout] 60 | fn route(ip: IP) {}
[INFO] [stdout]    |          ^^ help: if this is intentional, prefix it with an underscore: `_ip`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ip`
[INFO] [stdout]   --> enums/src/main.rs:62:11
[INFO] [stdout]    |
[INFO] [stdout] 62 | fn route2(ip: IP2) {}
[INFO] [stdout]    |           ^^ help: if this is intentional, prefix it with an underscore: `_ip`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> slices/src/main.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut s = String::from("hello world");
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v2`
[INFO] [stdout]  --> collections/src/main.rs:5:13
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut v2 = vec![1, 2, 3];
[INFO] [stdout]   |             ^^ help: if this is intentional, prefix it with an underscore: `_v2`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `JAPAN`
[INFO] [stdout]  --> enums/src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 |     JAPAN,
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `V6`
[INFO] [stdout]  --> enums/src/main.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 |     V6(String),
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0308`.
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `country`
[INFO] [stdout]   --> enums/src/main.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let country = Countries::UKRAINE;
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_country`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `country`
[INFO] [stdout]   --> enums/src/main.rs:58:11
[INFO] [stdout]    |
[INFO] [stdout] 58 | fn travel(country: Countries) {}
[INFO] [stdout]    |           ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_country`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ip`
[INFO] [stdout]   --> enums/src/main.rs:60:10
[INFO] [stdout]    |
[INFO] [stdout] 60 | fn route(ip: IP) {}
[INFO] [stdout]    |          ^^ help: if this is intentional, prefix it with an underscore: `_ip`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ip`
[INFO] [stdout]   --> enums/src/main.rs:62:11
[INFO] [stdout]    |
[INFO] [stdout] 62 | fn route2(ip: IP2) {}
[INFO] [stdout]    |           ^^ help: if this is intentional, prefix it with an underscore: `_ip`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> collections/src/main.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut v2 = vec![1, 2, 3];
[INFO] [stdout]   |         ----^^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v2`
[INFO] [stdout]  --> collections/src/main.rs:5:13
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut v2 = vec![1, 2, 3];
[INFO] [stdout]   |             ^^ help: if this is intentional, prefix it with an underscore: `_v2`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `generics` due to 3 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0106]: missing lifetime specifier
[INFO] [stdout]   --> references/src/main.rs:48:15
[INFO] [stdout]    |
[INFO] [stdout] 48 | fn func3() -> &String {
[INFO] [stdout]    |               ^ expected named lifetime parameter
[INFO] [stdout]    |
[INFO] [stdout]    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
[INFO] [stdout] help: consider using the `'static` lifetime
[INFO] [stdout]    |
[INFO] [stdout] 48 | fn func3() -> &'static String {
[INFO] [stdout]    |               ~~~~~~~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0106`.
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> collections/src/main.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut v2 = vec![1, 2, 3];
[INFO] [stdout]   |         ----^^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_file`
[INFO] [stdout]   --> exceptions/src/main.rs:19:4
[INFO] [stdout]    |
[INFO] [stdout] 19 | fn open_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_file_refactored`
[INFO] [stdout]   --> exceptions/src/main.rs:38:4
[INFO] [stdout]    |
[INFO] [stdout] 38 | fn open_file_refactored() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `JAPAN`
[INFO] [stdout]  --> enums/src/main.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 |     JAPAN,
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `V6`
[INFO] [stdout]  --> enums/src/main.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 |     V6(String),
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0106]: missing lifetime specifier
[INFO] [stdout]   --> references/src/main.rs:48:15
[INFO] [stdout]    |
[INFO] [stdout] 48 | fn func3() -> &String {
[INFO] [stdout]    |               ^ expected named lifetime parameter
[INFO] [stdout]    |
[INFO] [stdout]    = help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
[INFO] [stdout] help: consider using the `'static` lifetime
[INFO] [stdout]    |
[INFO] [stdout] 48 | fn func3() -> &'static String {
[INFO] [stdout]    |               ~~~~~~~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0106`.
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]   --> structs/src/main.rs:41:9
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let black = Color(0, 0, 0);
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `origin`
[INFO] [stdout]   --> structs/src/main.rs:42:9
[INFO] [stdout]    |
[INFO] [stdout] 42 |     let origin = Point(0, 0, 0);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_origin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user2`
[INFO] [stdout]   --> structs/src/main.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let user2 = User {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]   --> structs/src/main.rs:41:9
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let black = Color(0, 0, 0);
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `origin`
[INFO] [stdout]   --> structs/src/main.rs:42:9
[INFO] [stdout]    |
[INFO] [stdout] 42 |     let origin = Point(0, 0, 0);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_origin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user2`
[INFO] [stdout]   --> structs/src/main.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let user2 = User {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `alive` is assigned to, but never used
[INFO] [stdout]   --> lifetime/src/main.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let alive;
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout]    = note: consider using `_alive` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `alive` is never read
[INFO] [stdout]   --> lifetime/src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |         alive = AliveStructure {
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> lifetime/src/main.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let s: &'static str = "I have a static lifetime.";
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `longest_with_an_announcement`
[INFO] [stdout]   --> lifetime/src/main.rs:55:4
[INFO] [stdout]    |
[INFO] [stdout] 55 | fn longest_with_an_announcement<'a, T>(x: &'a str, y: &'a str, ann: T) -> &'a str
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_file`
[INFO] [stdout]   --> exceptions/src/main.rs:19:4
[INFO] [stdout]    |
[INFO] [stdout] 19 | fn open_file() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open_file_refactored`
[INFO] [stdout]   --> exceptions/src/main.rs:38:4
[INFO] [stdout]    |
[INFO] [stdout] 38 | fn open_file_refactored() -> Result<String, io::Error> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> generics/src/main.rs:50:73
[INFO] [stdout]    |
[INFO] [stdout] 50 | fn some_function<T: Display + Clone, U: Clone + Debug>(t: &T, u: &U) -> i32 {}
[INFO] [stdout]    |    -------------                                                        ^^^ expected `i32`, found `()`
[INFO] [stdout]    |    |
[INFO] [stdout]    |    implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0308]: mismatched types
[INFO] [stdout]   --> generics/src/main.rs:52:52
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn some_function_refactored<T, U>(t: &T, u: &U) -> i32
[INFO] [stdout]    |    ------------------------                        ^^^ expected `i32`, found `()`
[INFO] [stdout]    |    |
[INFO] [stdout]    |    implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]  --> slices/src/main.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let hello = &s[0..5];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `world`
[INFO] [stdout]  --> slices/src/main.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let world = &s[6..11];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_world`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> slices/src/main.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let slice = &a[1..3];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> slices/src/main.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut s = String::from("hello world");
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0308`.
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "a5ebdc75cfb4339b70cc9ce61426e312b73087f3ece7f21b5482ed04ee0e97ea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a5ebdc75cfb4339b70cc9ce61426e312b73087f3ece7f21b5482ed04ee0e97ea", kill_on_drop: false }`
[INFO] [stdout] a5ebdc75cfb4339b70cc9ce61426e312b73087f3ece7f21b5482ed04ee0e97ea
