[INFO] cloning repository https://github.com/BruceChar/LearnRustByExample
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/BruceChar/LearnRustByExample" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBruceChar%2FLearnRustByExample", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBruceChar%2FLearnRustByExample'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2150219561f9dd455dbbc74483301654dc899e9f
[INFO] checking BruceChar/LearnRustByExample against try#54cf65b8d066c082e536455049b95943cf30378f for pr-151920
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBruceChar%2FLearnRustByExample" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/BruceChar/LearnRustByExample
[INFO] finished tweaking git repo https://github.com/BruceChar/LearnRustByExample
[INFO] tweaked toml for git repo https://github.com/BruceChar/LearnRustByExample written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/BruceChar/LearnRustByExample on toolchain 54cf65b8d066c082e536455049b95943cf30378f
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+54cf65b8d066c082e536455049b95943cf30378f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/BruceChar/LearnRustByExample 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" "+54cf65b8d066c082e536455049b95943cf30378f" "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-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:61361fe0aef631f17e9d025a70c5a647956f8c671dd02950a60ad3f5cc5526d7" "/opt/rustwide/cargo-home/bin/cargo" "+54cf65b8d066c082e536455049b95943cf30378f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6fd2e434de587ee42e95e8c947d3b2e67a066eeabc313d9982c99362b65d0026
[INFO] running `Command { std: "docker" "start" "-a" "6fd2e434de587ee42e95e8c947d3b2e67a066eeabc313d9982c99362b65d0026", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6fd2e434de587ee42e95e8c947d3b2e67a066eeabc313d9982c99362b65d0026", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6fd2e434de587ee42e95e8c947d3b2e67a066eeabc313d9982c99362b65d0026", kill_on_drop: false }`
[INFO] [stdout] 6fd2e434de587ee42e95e8c947d3b2e67a066eeabc313d9982c99362b65d0026
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:61361fe0aef631f17e9d025a70c5a647956f8c671dd02950a60ad3f5cc5526d7" "/opt/rustwide/cargo-home/bin/cargo" "+54cf65b8d066c082e536455049b95943cf30378f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 69822c12f91cace2e4821336753d5b0cc176c1d6ac41587168ac5c43e59ab7b2
[INFO] running `Command { std: "docker" "start" "-a" "69822c12f91cace2e4821336753d5b0cc176c1d6ac41587168ac5c43e59ab7b2", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.80
[INFO] [stderr]    Compiling getrandom v0.1.15
[INFO] [stderr]     Checking another v0.1.0 (/opt/rustwide/workdir/src/another)
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking anolib v0.1.0 (/opt/rustwide/workdir/anolib)
[INFO] [stderr]     Checking mylib v0.1.0 (/opt/rustwide/workdir/mylib)
[INFO] [stderr]     Checking RustByExamples v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> examples/func.rs:9:27
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn factory(x: i32) -> Box<Fn(i32) -> i32> {
[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] 9 | fn factory(x: i32) -> Box<dyn Fn(i32) -> i32> {
[INFO] [stdout]   |                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::stdin`
[INFO] [stdout]  --> examples/struct.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::io::stdin;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Unit` is never constructed
[INFO] [stdout]  --> examples/struct.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | struct Unit;
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `name` and `age` are never read
[INFO] [stdout]   --> examples/struct.rs:12:3
[INFO] [stdout]    |
[INFO] [stdout] 11 | struct Person<'a> {
[INFO] [stdout]    |        ------ fields in this struct
[INFO] [stdout] 12 |   name: &'a str,
[INFO] [stdout]    |   ^^^^
[INFO] [stdout] 13 |   age: u8
[INFO] [stdout]    |   ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Person` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `p` and `sex` are never read
[INFO] [stdout]   --> examples/struct.rs:18:3
[INFO] [stdout]    |
[INFO] [stdout] 17 | struct Man<'a> {
[INFO] [stdout]    |        --- fields in this struct
[INFO] [stdout] 18 |   p: Person<'a>,
[INFO] [stdout]    |   ^
[INFO] [stdout] 19 |   sex: &'a str
[INFO] [stdout]    |   ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Man` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `function` is never used
[INFO] [stdout]   --> examples/mod.rs:40:4
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn function() {
[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 import: `std::rc::Rc`
[INFO] [stdout]  --> examples/thread.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::rc::Rc;
[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 imports: `Receiver` and `Sender`
[INFO] [stdout]  --> examples/channel.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Sender,
[INFO] [stdout]   |     ^^^^^^
[INFO] [stdout] 4 |     Receiver
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0433]: failed to resolve: use of unresolved module or unlinked crate `io`
[INFO] [stdout]   --> examples/channel.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     io::spawn();
[INFO] [stdout]    |     ^^ use of unresolved module or unlinked crate `io`
[INFO] [stdout]    |
[INFO] [stdout]    = help: if you wanted to use a crate named `io`, use `cargo add io` to add it to your `Cargo.toml`
[INFO] [stdout] help: a builtin type with a similar name exists
[INFO] [stdout]    |
[INFO] [stdout] 13 -     io::spawn();
[INFO] [stdout] 13 +     i8::spawn();
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0433`.
[INFO] [stdout] 
[INFO] [stdout] error[E0282]: type annotations needed for `HashMap<_, _>`
[INFO] [stdout]   --> examples/rc.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let m = HashMap::new();
[INFO] [stdout]    |         ^   -------------- type must be known at this point
[INFO] [stdout]    |
[INFO] [stdout] help: consider giving `m` an explicit type, where the type for type parameter `K` is specified
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let m: HashMap<K, V> = HashMap::new();
[INFO] [stdout]    |          +++++++++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `main1` is never used
[INFO] [stdout]  --> examples/thread.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn main1() {
[INFO] [stdout]   |    ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0282`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `RustByExamples` (example "rc") due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: enum `UsState` is never used
[INFO] [stdout]  --> examples/match.rs:3:6
[INFO] [stdout]   |
[INFO] [stdout] 3 | enum UsState {
[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 `Coin` is never used
[INFO] [stdout]   --> examples/match.rs:10:6
[INFO] [stdout]    |
[INFO] [stdout] 10 | enum Coin {
[INFO] [stdout]    |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `value_in_cents` is never used
[INFO] [stdout]   --> examples/match.rs:17:4
[INFO] [stdout]    |
[INFO] [stdout] 17 | fn value_in_cents(coin: Coin) -> u8 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `other_bind` is never used
[INFO] [stdout]   --> examples/match.rs:52:4
[INFO] [stdout]    |
[INFO] [stdout] 52 | fn other_bind(coin: Coin) {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `plus_one` is never used
[INFO] [stdout]   --> examples/match.rs:63:4
[INFO] [stdout]    |
[INFO] [stdout] 63 | fn plus_one(x: Option<i32>) -> Option<i32> {
[INFO] [stdout]    |    ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `count_without_quarter` is never used
[INFO] [stdout]   --> examples/match.rs:71:4
[INFO] [stdout]    |
[INFO] [stdout] 71 | fn count_without_quarter(coins: &Vec<Coin>) -> i32 {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `count_while` is never used
[INFO] [stdout]   --> examples/match.rs:86:4
[INFO] [stdout]    |
[INFO] [stdout] 86 | fn count_while(coins: &mut Vec<Coin>) -> i32 {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `RustByExamples` (example "channel") due to 1 previous error; 1 warning emitted
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> examples/demo.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut m = 9;
[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: `iter`
[INFO] [stdout]  --> examples/demo.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let iter = [1,2,3].iter();
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_iter`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `m1` is never read
[INFO] [stdout]  --> examples/demo.rs:3:18
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let mut m1 = m;
[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: unused label
[INFO] [stdout]  --> examples/loop.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |         'inner: loop {
[INFO] [stdout]   |         ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_labels)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0283]: type annotations needed
[INFO] [stdout]  --> examples/loop.rs:4:25
[INFO] [stdout]   |
[INFO] [stdout] 4 |     v.iter().map(|x| x).collect();
[INFO] [stdout]   |                         ^^^^^^^ cannot infer type of the type parameter `B` declared on the method `collect`
[INFO] [stdout]   |
[INFO] [stdout]   = note: cannot satisfy `_: FromIterator<&i32>`
[INFO] [stdout] note: required by a bound in `collect`
[INFO] [stdout]  --> /rustc/54cf65b8d066c082e536455049b95943cf30378f/library/core/src/iter/traits/iterator.rs:2051:4
[INFO] [stdout] help: consider specifying the generic argument
[INFO] [stdout]   |
[INFO] [stdout] 4 |     v.iter().map(|x| x).collect::<Vec<_>>();
[INFO] [stdout]   |                                ++++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0283`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `RustByExamples` (example "loop") due to 1 previous error; 1 warning emitted
[INFO] [stdout] warning: unused import: `std::fmt::Display`
[INFO] [stdout]  --> examples/generic.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::fmt::Display;
[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: `Lines as iLines`
[INFO] [stdout]  --> examples/generic.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{Lines as iLines, BufReader, BufRead};
[INFO] [stdout]   |               ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::str::Lines`
[INFO] [stdout]  --> examples/generic.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::str::Lines;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `lines`
[INFO] [stdout]   --> examples/generic.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let lines = "some\nniubi\nstring".lines();
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_lines`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "69822c12f91cace2e4821336753d5b0cc176c1d6ac41587168ac5c43e59ab7b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "69822c12f91cace2e4821336753d5b0cc176c1d6ac41587168ac5c43e59ab7b2", kill_on_drop: false }`
[INFO] [stdout] 69822c12f91cace2e4821336753d5b0cc176c1d6ac41587168ac5c43e59ab7b2
