[INFO] cloning repository https://github.com/yew1eb/rustlab
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/yew1eb/rustlab" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyew1eb%2Frustlab", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyew1eb%2Frustlab'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3ccf8588ba87d3ef5505dfdf8ef1bf9c93fa192e
[INFO] checking yew1eb/rustlab against 1.55.0 for beta-1.56-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fyew1eb%2Frustlab" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/yew1eb/rustlab on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/yew1eb/rustlab
[INFO] finished tweaking git repo https://github.com/yew1eb/rustlab
[INFO] tweaked toml for git repo https://github.com/yew1eb/rustlab written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/yew1eb/rustlab already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] f11f086111eee4a35de077d17eff269950b8c48b9c7c61c3888d3c221797e894
[INFO] running `Command { std: "docker" "start" "-a" "f11f086111eee4a35de077d17eff269950b8c48b9c7c61c3888d3c221797e894", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f11f086111eee4a35de077d17eff269950b8c48b9c7c61c3888d3c221797e894", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f11f086111eee4a35de077d17eff269950b8c48b9c7c61c3888d3c221797e894", kill_on_drop: false }`
[INFO] [stdout] f11f086111eee4a35de077d17eff269950b8c48b9c7c61c3888d3c221797e894
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+1.55.0" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8be9910f9481c2f7e0decbc81531e085a4fd2483b816ddab8b1b697329d3bb2b
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "8be9910f9481c2f7e0decbc81531e085a4fd2483b816ddab8b1b697329d3bb2b", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.48
[INFO] [stderr]     Checking futures-core v0.3.7
[INFO] [stderr]     Checking futures-sink v0.3.7
[INFO] [stderr]     Checking futures-io v0.3.7
[INFO] [stderr]     Checking once_cell v1.4.1
[INFO] [stderr]     Checking object v0.22.0
[INFO] [stderr]     Checking match_cfg v0.1.0
[INFO] [stderr]     Checking linked-hash-map v0.5.3
[INFO] [stderr]    Compiling encoding_rs v0.8.26
[INFO] [stderr]    Compiling bindgen v0.57.0
[INFO] [stderr]    Compiling regex-syntax v0.6.25
[INFO] [stderr]     Checking humantime v2.0.1
[INFO] [stderr]     Checking mylib v0.1.0 (/opt/rustwide/workdir/example-projects/trpl-webserver/mylib)
[INFO] [stderr]     Checking home v0.5.3
[INFO] [stderr]     Checking json v0.12.4
[INFO] [stderr]     Checking rustlab v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking instant v0.1.8
[INFO] [stdout] warning: field is never read: `id`
[INFO] [stdout]  --> example-projects/trpl-webserver/mylib/src/lib.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     id: usize,
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling miniz_oxide v0.4.3
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling time v0.2.22
[INFO] [stdout] warning: field is never read: `id`
[INFO] [stdout]  --> example-projects/trpl-webserver/mylib/src/lib.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     id: usize,
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling cookie v0.14.3
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking bytestring v0.1.5
[INFO] [stderr]     Checking addr2line v0.14.0
[INFO] [stderr]    Compiling clang-sys v1.2.0
[INFO] [stderr]     Checking humantime v1.3.0
[INFO] [stderr]     Checking tinyvec v1.0.1
[INFO] [stderr]    Compiling mysqlclient-sys v0.2.4
[INFO] [stderr]     Checking futures-channel v0.3.7
[INFO] [stderr]    Compiling libc v0.2.80
[INFO] [stderr]     Checking trpl-webserver v0.1.0 (/opt/rustwide/workdir/example-projects/trpl-webserver)
[INFO] [stderr]     Checking futures-task v0.3.7
[INFO] [stderr]     Checking idna v0.1.5
[INFO] [stderr]     Checking lru-cache v0.1.2
[INFO] [stderr]     Checking iovec v0.1.4
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[INFO] [stderr]     Checking signal-hook-registry v1.2.2
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[INFO] [stderr]     Checking time v0.1.44
[INFO] [stderr]     Checking wait-timeout v0.2.0
[INFO] [stderr]    Compiling aho-corasick v0.7.18
[INFO] [stderr]     Checking tracing v0.1.21
[INFO] [stderr]    Compiling nom v5.1.2
[INFO] [stderr]     Checking regex-automata v0.1.9
[INFO] [stderr]     Checking regex v1.5.3
[INFO] [stderr]     Checking resolv-conf v0.6.3
[INFO] [stderr]     Checking threadpool v1.8.1
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking parking_lot v0.11.0
[INFO] [stderr]     Checking crossbeam-channel v0.4.4
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking mio v0.6.22
[INFO] [stderr]    Compiling jobserver v0.1.21
[INFO] [stderr]     Checking bstr v0.2.16
[INFO] [stderr]     Checking sha-1 v0.9.2
[INFO] [stderr]     Checking url v1.7.2
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking scheduled-thread-pool v0.2.5
[INFO] [stderr]    Compiling cc v1.0.61
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]     Checking r2d2 v0.8.9
[INFO] [stderr]     Checking flate2 v1.0.19
[INFO] [stderr]     Checking env_logger v0.8.1
[INFO] [stderr]     Checking predicates v1.0.8
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]     Checking basic-exercises v0.1.0 (/opt/rustwide/workdir/basic-exercises)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> basic-exercises/src/closure_base.rs:1:27
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn counter(i: i32) -> Box<Fn(i32) -> i32> {
[INFO] [stdout]   |                           ^^^^^^^^^^^^^^ help: use `dyn`: `dyn Fn(i32) -> i32`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[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 issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused macro definition
[INFO] [stdout]  --> basic-exercises/src/macros_base.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | / macro_rules! say_hello {
[INFO] [stdout] 2 | |     // `()` 表示此宏不接受任何参数。
[INFO] [stdout] 3 | |     () => {
[INFO] [stdout] 4 | |         // 此宏将会展开成这个代码块里面的内容。
[INFO] [stdout] 5 | |         println!("Hello!");
[INFO] [stdout] 6 | |     };
[INFO] [stdout] 7 | | }
[INFO] [stdout]   | |_^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_macros)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused macro definition
[INFO] [stdout]   --> basic-exercises/src/macros_base.rs:26:1
[INFO] [stdout]    |
[INFO] [stdout] 26 | / macro_rules! print_result {
[INFO] [stdout] 27 | |     // 此宏接受一个 `expr` 类型的表达式，将它转换成一个字符串，
[INFO] [stdout] 28 | |     // 并伴随着表达式的结果。
[INFO] [stdout] 29 | |     // `expr` 指示符用于表达式。
[INFO] [stdout] ...  |
[INFO] [stdout] 34 | |     };
[INFO] [stdout] 35 | | }
[INFO] [stdout]    | |_^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused macro definition
[INFO] [stdout]   --> basic-exercises/src/macros_base.rs:39:1
[INFO] [stdout]    |
[INFO] [stdout] 39 | / macro_rules! test {
[INFO] [stdout] 40 | |     // 参数不需要使用逗号隔开。
[INFO] [stdout] 41 | |     // 可以使用任意模板（原文：Any template can be used!）！
[INFO] [stdout] 42 | |     ($left:expr; and $right:expr) => {
[INFO] [stdout] ...  |
[INFO] [stdout] 58 | |     };
[INFO] [stdout] 59 | | }
[INFO] [stdout]    | |_^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused macro definition
[INFO] [stdout]   --> basic-exercises/src/macros_base.rs:62:1
[INFO] [stdout]    |
[INFO] [stdout] 62 | / macro_rules! find_min {
[INFO] [stdout] 63 | |     // 基本情形：
[INFO] [stdout] 64 | |     ($x:expr) => ($x);
[INFO] [stdout] 65 | |     // `$x` 后面跟着至少一个 `$y,`
[INFO] [stdout] ...  |
[INFO] [stdout] 69 | |     )
[INFO] [stdout] 70 | | }
[INFO] [stdout]    | |_^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::mem`
[INFO] [stdout]  --> basic-exercises/src/std_box_base.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::mem;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]  --> basic-exercises/src/main.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![warn(unused_imports)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]  --> basic-exercises/src/std_hashmap_base.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::collections::HashMap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::HashSet`
[INFO] [stdout]  --> basic-exercises/src/std_hashset_base.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::collections::HashSet;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::sync::mpsc`
[INFO] [stdout]  --> basic-exercises/src/std_misc_channels_base.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::sync::mpsc;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Receiver`, `Sender`
[INFO] [stdout]  --> basic-exercises/src/std_misc_channels_base.rs:2:23
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::sync::mpsc::{Receiver, Sender};
[INFO] [stdout]   |                       ^^^^^^^^  ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread`
[INFO] [stdout]  --> basic-exercises/src/std_misc_channels_base.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::thread;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::env`
[INFO] [stdout]  --> basic-exercises/src/std_misc_env_arg_base.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::env;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fs`
[INFO] [stdout]  --> basic-exercises/src/std_misc_io_fs_base.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::fs;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::os::unix`
[INFO] [stdout]  --> basic-exercises/src/std_misc_io_fs_base.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::os::unix;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::error::Error`
[INFO] [stdout]  --> basic-exercises/src/std_misc_path_file_base.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::error::Error;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::fs::File`
[INFO] [stdout]  --> basic-exercises/src/std_misc_path_file_base.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::fs::File;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::prelude::*`
[INFO] [stdout]  --> basic-exercises/src/std_misc_path_file_base.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::io::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::path::Path`
[INFO] [stdout]  --> basic-exercises/src/std_misc_path_file_base.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::path::Path;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::error::Error`
[INFO] [stdout]  --> basic-exercises/src/std_misc_process_base.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::error::Error;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::prelude::*`
[INFO] [stdout]  --> basic-exercises/src/std_misc_process_base.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Command`, `Stdio`
[INFO] [stdout]  --> basic-exercises/src/std_misc_process_base.rs:3:20
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::process::{Command, Stdio};
[INFO] [stdout]   |                    ^^^^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread`
[INFO] [stdout]  --> basic-exercises/src/std_misc_threads_base.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::thread;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]  --> basic-exercises/src/basic_type.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     use super::*;
[INFO] [stdout]   |         ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]  --> basic-exercises/src/main.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![warn(unused_imports)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> basic-exercises/src/closure_base.rs:1:27
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn counter(i: i32) -> Box<Fn(i32) -> i32> {
[INFO] [stdout]   |                           ^^^^^^^^^^^^^^ help: use `dyn`: `dyn Fn(i32) -> i32`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[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 issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::*`
[INFO] [stdout]  --> basic-exercises/src/collection_types.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     use super::*;
[INFO] [stdout]   |         ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused label
[INFO] [stdout]   --> basic-exercises/src/loops.rs:14:17
[INFO] [stdout]    |
[INFO] [stdout] 14 |                 'second_loop: loop {
[INFO] [stdout]    |                 ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_labels)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Receiver`, `Sender`
[INFO] [stdout]  --> basic-exercises/src/std_misc_channels_base.rs:2:23
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::sync::mpsc::{Receiver, Sender};
[INFO] [stdout]   |                       ^^^^^^^^  ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::env`
[INFO] [stdout]  --> basic-exercises/src/std_misc_env_arg_base.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::env;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> basic-exercises/src/std_vector_base.rs:72:10
[INFO] [stdout]    |
[INFO] [stdout] 72 |         };
[INFO] [stdout]    |          ^ help: remove this semicolon
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(redundant_semicolons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary trailing semicolon
[INFO] [stdout]   --> basic-exercises/src/struct_base.rs:48:20
[INFO] [stdout]    |
[INFO] [stdout] 48 |         struct A {};
[INFO] [stdout]    |                    ^ help: remove this semicolon
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stdout] warning: unused variable: `population`
[INFO] [stdout]   --> basic-exercises/src/destructuring_base.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |         population,
[INFO] [stdout]    |         ^^^^^^^^^^ help: try ignoring the field: `population: _`
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> basic-exercises/src/main.rs:2:9
[INFO] [stdout]    |
[INFO] [stdout] 2  | #![warn(unused_variables)]
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `date_founded`
[INFO] [stdout]   --> basic-exercises/src/destructuring_base.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |         date_founded,
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: try ignoring the field: `date_founded: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking tokio v0.2.22
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]   --> basic-exercises/src/std_result_base.rs:87:28
[INFO] [stdout]    |
[INFO] [stdout] 87 |           Err(why) => panic!(match why {
[INFO] [stdout]    |  ____________________________^
[INFO] [stdout] 88 | |             checked::MathError::NegativeLogarithm => "logarithm of negative number",
[INFO] [stdout] 89 | |             checked::MathError::DivisionByZero => "division by zero",
[INFO] [stdout] 90 | |             checked::MathError::NegativeSquareRoot => "square root of negative number",
[INFO] [stdout] 91 | |         }),
[INFO] [stdout]    | |_________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]    = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout] help: add a "{}" format string to Display the message
[INFO] [stdout]    |
[INFO] [stdout] 87 |         Err(why) => panic!("{}", match why {
[INFO] [stdout]    |                            ^^^^^
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]    |
[INFO] [stdout] 87 |         Err(why) => std::panic::panic_any(match why {
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 25 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> basic-exercises/src/std_misc_path_file_base.rs:42:69
[INFO] [stdout]    |
[INFO] [stdout] 42 |             Err(why) => panic!("couldn't open {}: {}", display, why.description()),
[INFO] [stdout]    |                                                                     ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> basic-exercises/src/std_misc_path_file_base.rs:49:69
[INFO] [stdout]    |
[INFO] [stdout] 49 |             Err(why) => panic!("couldn't read {}: {}", display, why.description()),
[INFO] [stdout]    |                                                                     ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> basic-exercises/src/std_misc_path_file_base.rs:72:71
[INFO] [stdout]    |
[INFO] [stdout] 72 |             Err(why) => panic!("couldn't create {}: {}", display, why.description()),
[INFO] [stdout]    |                                                                       ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> basic-exercises/src/std_misc_path_file_base.rs:78:73
[INFO] [stdout]    |
[INFO] [stdout] 78 |             Err(why) => panic!("couldn't write to {}: {}", display, why.description()),
[INFO] [stdout]    |                                                                         ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking assert_cmd v1.0.3
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> basic-exercises/src/std_misc_process_base.rs:37:61
[INFO] [stdout]    |
[INFO] [stdout] 37 |             Err(why) => panic!("couldn't spawn wc: {}", why.description()),
[INFO] [stdout]    |                                                             ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> basic-exercises/src/std_misc_process_base.rs:48:70
[INFO] [stdout]    |
[INFO] [stdout] 48 |             Err(why) => panic!("couldn't write to wc stdin: {}", why.description()),
[INFO] [stdout]    |                                                                      ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> basic-exercises/src/std_misc_process_base.rs:59:67
[INFO] [stdout]    |
[INFO] [stdout] 59 |             Err(why) => panic!("couldn't read wc stdout: {}", why.description()),
[INFO] [stdout]    |                                                                   ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]   --> basic-exercises/src/basic_type.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 | /         if let y = 5 {
[INFO] [stdout] 27 | |             println!("{}", y);
[INFO] [stdout] 28 | |         }
[INFO] [stdout]    | |_________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout]    = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]    = help: consider replacing the `if let` with a `let`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `str1`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:255:21
[INFO] [stdout]     |
[INFO] [stdout] 255 |             let mut str1 = String::from("hello");
[INFO] [stdout]     |                     ^^^^ help: if this is intentional, prefix it with an underscore: `_str1`
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> basic-exercises/src/main.rs:2:9
[INFO] [stdout]     |
[INFO] [stdout] 2   | #![warn(unused_variables)]
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> basic-exercises/src/basic_type.rs:25:13
[INFO] [stdout]    |
[INFO] [stdout] 25 |         let x = 5;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `a` is never read
[INFO] [stdout]   --> basic-exercises/src/basic_type.rs:84:17
[INFO] [stdout]    |
[INFO] [stdout] 84 |         let mut a: f64 = 1.0;
[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: `b`
[INFO] [stdout]   --> basic-exercises/src/basic_type.rs:85:13
[INFO] [stdout]    |
[INFO] [stdout] 85 |         let b = 2.0f32;
[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]   --> basic-exercises/src/basic_type.rs:90:13
[INFO] [stdout]    |
[INFO] [stdout] 90 |         let a = a; //不能赋值
[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]   --> basic-exercises/src/basic_type.rs:99:13
[INFO] [stdout]    |
[INFO] [stdout] 99 |         let b: [u8; 3] = [8, 6, 5];
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice_complete`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:105:13
[INFO] [stdout]     |
[INFO] [stdout] 105 |         let slice_complete = &arr[..]; // 获取全部元素
[INFO] [stdout]     |             ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice_complete`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice_middle`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:106:13
[INFO] [stdout]     |
[INFO] [stdout] 106 |         let slice_middle = &arr[1..4]; // 获取中间元素，最后取得的 Slice 为 [2, 3, 4] 。切片遵循左 闭右开原则。
[INFO] [stdout]     |             ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice_middle`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice_right`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:107:13
[INFO] [stdout]     |
[INFO] [stdout] 107 |         let slice_right = &arr[1..]; // 最后获得的元素为[2, 3, 4, 5, 6]，长度为 5。
[INFO] [stdout]     |             ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice_right`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice_left`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:108:13
[INFO] [stdout]     |
[INFO] [stdout] 108 |         let slice_left = &arr[..3]; // 最后获得的元素为[1, 2, 3]，长度为 3。
[INFO] [stdout]     |             ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice_left`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v2`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:112:13
[INFO] [stdout]     |
[INFO] [stdout] 112 |         let v2 = vec![0; 10]; // 声明一个初始长度为 10 的值全为 0 的动态数组
[INFO] [stdout]     |             ^^ help: if this is intentional, prefix it with an underscore: `_v2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:147:37
[INFO] [stdout]     |
[INFO] [stdout] 147 |             Message::ChangeColor(x, y, z) => println!("{}", x),
[INFO] [stdout]     |                                     ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:147:40
[INFO] [stdout]     |
[INFO] [stdout] 147 |             Message::ChangeColor(x, y, z) => println!("{}", x),
[INFO] [stdout]     |                                        ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:150:36
[INFO] [stdout]     |
[INFO] [stdout] 150 |             Message::Location { x, y } => println!("{}", x),
[INFO] [stdout]     |                                    ^ help: try ignoring the field: `y: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `d`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:168:13
[INFO] [stdout]     |
[INFO] [stdout] 168 |         let d: &'static str = r"abc \n abc"; //等 价于
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_d`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:169:13
[INFO] [stdout]     |
[INFO] [stdout] 169 |         let c: &'static str = "abc \\n abc";
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `number_word_hashmap2`
[INFO] [stdout]   --> basic-exercises/src/closure_base.rs:51:13
[INFO] [stdout]    |
[INFO] [stdout] 51 |         let number_word_hashmap2: HashMap<_, _> = some_numbers
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_number_word_hashmap2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> basic-exercises/src/collection_types.rs:58:14
[INFO] [stdout]    |
[INFO] [stdout] 58 |         let (a, b, _) = (str_vec[0], str_vec[1], str_vec[2]);
[INFO] [stdout]    |              ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `population`
[INFO] [stdout]   --> basic-exercises/src/destructuring_base.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |         population,
[INFO] [stdout]    |         ^^^^^^^^^^ help: try ignoring the field: `population: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `date_founded`
[INFO] [stdout]   --> basic-exercises/src/destructuring_base.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |         date_founded,
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: try ignoring the field: `date_founded: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i1`
[INFO] [stdout]   --> basic-exercises/src/enum_base.rs:46:13
[INFO] [stdout]    |
[INFO] [stdout] 46 |         let i1 = IpAddr {
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_i1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i2`
[INFO] [stdout]   --> basic-exercises/src/enum_base.rs:50:13
[INFO] [stdout]    |
[INFO] [stdout] 50 |         let i2 = IpAddr {
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_i2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i1`
[INFO] [stdout]   --> basic-exercises/src/enum_base.rs:60:13
[INFO] [stdout]    |
[INFO] [stdout] 60 |         let i1 = IpAddr2::V4(String::from("127.0.0.1"));
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_i1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i2`
[INFO] [stdout]   --> basic-exercises/src/enum_base.rs:61:13
[INFO] [stdout]    |
[INFO] [stdout] 61 |         let i2 = IpAddr2::V6(String::from("::1"));
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_i2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i1`
[INFO] [stdout]   --> basic-exercises/src/enum_base.rs:68:13
[INFO] [stdout]    |
[INFO] [stdout] 68 |         let i1 = IpAddr3::V4(127, 0, 0, 1);
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_i1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i2`
[INFO] [stdout]   --> basic-exercises/src/enum_base.rs:69:13
[INFO] [stdout]    |
[INFO] [stdout] 69 |         let i2 = IpAddr3::V6(String::from("::1"));
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_i2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> basic-exercises/src/fn_base.rs:35:13
[INFO] [stdout]    |
[INFO] [stdout] 35 |         let a: i32 = square(37, 41);
[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]   --> basic-exercises/src/fn_base.rs:36:13
[INFO] [stdout]    |
[INFO] [stdout] 36 |         let b: f64 = square(37.2, 41.1);
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `magic2`
[INFO] [stdout]   --> basic-exercises/src/lifetime_base.rs:76:17
[INFO] [stdout]    |
[INFO] [stdout] 76 |             let magic2 = String::from("shazam!");
[INFO] [stdout]    |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_magic2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `fox`
[INFO] [stdout]    --> basic-exercises/src/lifetime_base.rs:102:13
[INFO] [stdout]     |
[INFO] [stdout] 102 |         let fox = Highlight(&text[4..19]);
[INFO] [stdout]     |             ^^^ help: if this is intentional, prefix it with an underscore: `_fox`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `dog`
[INFO] [stdout]    --> basic-exercises/src/lifetime_base.rs:103:13
[INFO] [stdout]     |
[INFO] [stdout] 103 |         let dog = Highlight(&text[35..43]);
[INFO] [stdout]     |             ^^^ help: if this is intentional, prefix it with an underscore: `_dog`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `display`
[INFO] [stdout]   --> basic-exercises/src/std_misc_path_file_base.rs:18:13
[INFO] [stdout]    |
[INFO] [stdout] 18 |         let display = path.display();
[INFO] [stdout]    |             ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_display`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_number`
[INFO] [stdout]   --> basic-exercises/src/std_option_base.rs:22:13
[INFO] [stdout]    |
[INFO] [stdout] 22 |         let some_number = Some(5);
[INFO] [stdout]    |             ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> basic-exercises/src/std_option_base.rs:23:13
[INFO] [stdout]    |
[INFO] [stdout] 23 |         let some_string = Some(String::from("a string"));
[INFO] [stdout]    |             ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `absent_number`
[INFO] [stdout]   --> basic-exercises/src/std_option_base.rs:24:13
[INFO] [stdout]    |
[INFO] [stdout] 24 |         let absent_number: Option<i32> = None;
[INFO] [stdout]    |             ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_absent_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> basic-exercises/src/std_vector_base.rs:38:17
[INFO] [stdout]    |
[INFO] [stdout] 38 |         let mut v: Vec<i32> = Vec::new();
[INFO] [stdout]    |                 ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v1`
[INFO] [stdout]   --> basic-exercises/src/std_vector_base.rs:43:17
[INFO] [stdout]    |
[INFO] [stdout] 43 |             let v1 = vec![1, 2, 3];
[INFO] [stdout]    |                 ^^ help: if this is intentional, prefix it with an underscore: `_v1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> basic-exercises/src/std_vector_base.rs:74:13
[INFO] [stdout]    |
[INFO] [stdout] 74 |         let c = vec![
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> basic-exercises/src/struct_base.rs:44:13
[INFO] [stdout]    |
[INFO] [stdout] 44 |         let b = Point(30, 11);
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:210:17
[INFO] [stdout]     |
[INFO] [stdout] 210 |             let mut str2 = &mut str1;
[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: variable does not need to be mutable
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:214:17
[INFO] [stdout]     |
[INFO] [stdout] 214 |             let mut str3 = &mut str1;
[INFO] [stdout]     |                 ----^^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:234:17
[INFO] [stdout]     |
[INFO] [stdout] 234 |             let mut v2 = &mut v1;
[INFO] [stdout]     |                 ----^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:237:17
[INFO] [stdout]     |
[INFO] [stdout] 237 |             let mut v3 = &mut v1;
[INFO] [stdout]     |                 ----^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:255:17
[INFO] [stdout]     |
[INFO] [stdout] 255 |             let mut str1 = String::from("hello");
[INFO] [stdout]     |                 ----^^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:275:17
[INFO] [stdout]     |
[INFO] [stdout] 275 |             let mut a = String::from("testa 你好");
[INFO] [stdout]     |                 ----^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:276:17
[INFO] [stdout]     |
[INFO] [stdout] 276 |             let mut b = &a[0..4];
[INFO] [stdout]     |                 ----^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:284:21
[INFO] [stdout]     |
[INFO] [stdout] 284 |                 let mut a = String::from("testa 你好");
[INFO] [stdout]     |                     ----^
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> basic-exercises/src/basic_type.rs:290:21
[INFO] [stdout]     |
[INFO] [stdout] 290 |                 let mut b = &mut a;
[INFO] [stdout]     |                     ----^
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking backtrace v0.3.54
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> basic-exercises/src/std_vector_base.rs:38:13
[INFO] [stdout]    |
[INFO] [stdout] 38 |         let mut v: Vec<i32> = Vec::new();
[INFO] [stdout]    |             ----^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]   --> basic-exercises/src/std_result_base.rs:87:28
[INFO] [stdout]    |
[INFO] [stdout] 87 |           Err(why) => panic!(match why {
[INFO] [stdout]    |  ____________________________^
[INFO] [stdout] 88 | |             checked::MathError::NegativeLogarithm => "logarithm of negative number",
[INFO] [stdout] 89 | |             checked::MathError::DivisionByZero => "division by zero",
[INFO] [stdout] 90 | |             checked::MathError::NegativeSquareRoot => "square root of negative number",
[INFO] [stdout] 91 | |         }),
[INFO] [stdout]    | |_________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]    = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout] help: add a "{}" format string to Display the message
[INFO] [stdout]    |
[INFO] [stdout] 87 |         Err(why) => panic!("{}", match why {
[INFO] [stdout]    |                            ^^^^^
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]    |
[INFO] [stdout] 87 |         Err(why) => std::panic::panic_any(match why {
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 66 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling brotli-sys v0.3.2
[INFO] [stderr]    Compiling cexpr v0.4.0
[INFO] [stderr]     Checking brotli2 v0.3.2
[INFO] [stderr]     Checking tokio-util v0.3.1
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling pin-project-internal v1.0.1
[INFO] [stderr]    Compiling futures-macro v0.3.7
[INFO] [stderr]    Compiling pin-project-internal v0.4.27
[INFO] [stderr]    Compiling serde_derive v1.0.117
[INFO] [stderr]    Compiling derive_more v0.99.11
[INFO] [stderr]    Compiling actix-macros v0.1.2
[INFO] [stderr]    Compiling thiserror-impl v1.0.21
[INFO] [stderr]    Compiling enum-as-inner v0.3.3
[INFO] [stderr]    Compiling async-trait v0.1.41
[INFO] [stderr]    Compiling time-macros-impl v0.1.1
[INFO] [stderr]    Compiling actix-web-codegen v0.4.0
[INFO] [stderr]    Compiling actix_derive v0.5.0
[INFO] [stderr]    Compiling structopt-derive v0.4.14
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling diesel_derives v1.4.1
[INFO] [stderr]     Checking time-macros v0.1.1
[INFO] [stderr]    Compiling librocksdb-sys v6.17.3
[INFO] [stderr]     Checking thiserror v1.0.21
[INFO] [stderr]     Checking failure v0.1.8
[INFO] [stderr]     Checking pin-project v0.4.27
[INFO] [stderr]     Checking actix-codec v0.3.0
[INFO] [stderr]     Checking tracing-futures v0.2.4
[INFO] [stderr]     Checking pin-project v1.0.1
[INFO] [stderr]     Checking futures-util v0.3.7
[INFO] [stderr]     Checking structopt v0.3.21
[INFO] [stderr]     Checking actix-threadpool v0.3.3
[INFO] [stderr]     Checking serde v1.0.117
[INFO] [stderr]     Checking actix-rt v1.1.1
[INFO] [stderr]     Checking actix-service v1.0.6
[INFO] [stderr]     Checking futures v0.3.7
[INFO] [stderr]     Checking h2 v0.2.7
[INFO] [stderr]     Checking trust-dns-proto v0.19.5
[INFO] [stderr]     Checking actix-utils v2.0.0
[INFO] [stderr]     Checking actix-server v1.0.4
[INFO] [stderr]     Checking actix-tls v2.0.0
[INFO] [stderr] error: could not compile `serde`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustc --crate-name serde /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/serde-1.0.117/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C debuginfo=2 --cfg 'feature="default"' --cfg 'feature="derive"' --cfg 'feature="serde_derive"' --cfg 'feature="std"' -C metadata=83e16311a0785677 -C extra-filename=-83e16311a0785677 --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern serde_derive=/opt/rustwide/target/debug/deps/libserde_derive-50aeb92605402c3c.so --cap-lints allow --cap-lints=warn --cfg ops_bound --cfg core_reverse --cfg de_boxed_c_str --cfg de_boxed_path --cfg de_rc_dst --cfg core_duration --cfg integer128 --cfg range_inclusive --cfg num_nonzero --cfg core_try_from --cfg num_nonzero_signed --cfg std_atomic64 --cfg std_atomic` (signal: 9, SIGKILL: kill)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] The following warnings were emitted during compilation:
[INFO] [stderr] 
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] warning: c++: fatal error: Killed signal terminated program cc1plus
[INFO] [stderr] warning: compilation terminated.
[INFO] [stderr] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "8be9910f9481c2f7e0decbc81531e085a4fd2483b816ddab8b1b697329d3bb2b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8be9910f9481c2f7e0decbc81531e085a4fd2483b816ddab8b1b697329d3bb2b", kill_on_drop: false }`
[INFO] [stdout] 8be9910f9481c2f7e0decbc81531e085a4fd2483b816ddab8b1b697329d3bb2b
