[INFO] cloning repository https://github.com/randomdevforyou/rust-random
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/randomdevforyou/rust-random" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frandomdevforyou%2Frust-random", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frandomdevforyou%2Frust-random'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0f845e76aa144b7f45e93d91104058744d870859
[INFO] building randomdevforyou/rust-random against try#334963c956d25708feab489a3816ae63f639355d for pr-135216-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frandomdevforyou%2Frust-random" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/randomdevforyou/rust-random on toolchain 334963c956d25708feab489a3816ae63f639355d
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+334963c956d25708feab489a3816ae63f639355d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/randomdevforyou/rust-random
[INFO] finished tweaking git repo https://github.com/randomdevforyou/rust-random
[INFO] tweaked toml for git repo https://github.com/randomdevforyou/rust-random written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/randomdevforyou/rust-random 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" "+334963c956d25708feab489a3816ae63f639355d" "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-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+334963c956d25708feab489a3816ae63f639355d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c383f3e2d0681f422537537172d3799bb19b2d49012a089b8b4f661a1359065d
[INFO] running `Command { std: "docker" "start" "-a" "c383f3e2d0681f422537537172d3799bb19b2d49012a089b8b4f661a1359065d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c383f3e2d0681f422537537172d3799bb19b2d49012a089b8b4f661a1359065d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c383f3e2d0681f422537537172d3799bb19b2d49012a089b8b4f661a1359065d", kill_on_drop: false }`
[INFO] [stdout] c383f3e2d0681f422537537172d3799bb19b2d49012a089b8b4f661a1359065d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+334963c956d25708feab489a3816ae63f639355d" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 24c3dd0b3c9db9fe285acf5fc1b652dddb6f96d0fc2105cb89268bc8f2bce5a4
[INFO] running `Command { std: "docker" "start" "-a" "24c3dd0b3c9db9fe285acf5fc1b652dddb6f96d0fc2105cb89268bc8f2bce5a4", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling regex-syntax v0.7.2
[INFO] [stderr]    Compiling aho-corasick v1.0.2
[INFO] [stderr]    Compiling regex v1.8.4
[INFO] [stderr]    Compiling rust-random v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::iter`
[INFO] [stdout]  --> src/iterator.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::iter;
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]  --> src/problems/cat.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::collections::HashMap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iter`
[INFO] [stdout]    --> src/iterator.rs:128:13
[INFO] [stdout]     |
[INFO] [stdout] 128 |     let mut iter = a.iter();
[INFO] [stdout]     |             ^^^^ help: if this is intentional, prefix it with an underscore: `_iter`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]  --> src/strings.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let hello = String::from("Hello"); //immutable string
[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: `hello_slice`
[INFO] [stdout]   --> src/strings.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let hello_slice = &mut hello[0..5];
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_hello_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word_slice`
[INFO] [stdout]   --> src/strings.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let word_slice = &mut hello[7..];
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_word_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reverse`
[INFO] [stdout]   --> src/strings.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let reverse = hello.chars().rev().collect::<String>();
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reverse`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello_world_string`
[INFO] [stdout]   --> src/strings2.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let hello_world_string = hello_string + &world_string; // It takes ownership of hello_string and returns it back    
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_hello_world_string`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_str`
[INFO] [stdout]    --> src/strings2.rs:100:9
[INFO] [stdout]     |
[INFO] [stdout] 100 |     let new_str = hello_str.push('o');
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_str`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_str2`
[INFO] [stdout]    --> src/strings2.rs:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     let new_str2 = hello_str.push_str(", World");
[INFO] [stdout]     |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_str2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]    --> src/strings2.rs:111:9
[INFO] [stdout]     |
[INFO] [stdout] 111 |     let first = &hello_str[0..1];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `second`
[INFO] [stdout]    --> src/strings2.rs:113:9
[INFO] [stdout]     |
[INFO] [stdout] 113 |     let second = &hello_str[1..2];
[INFO] [stdout]     |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_second`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/strings2.rs:69:9
[INFO] [stdout]    |
[INFO] [stdout] 69 |     let mut hello_string = "Hello".to_string();
[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: `second`
[INFO] [stdout]   --> src/vectors.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let second = v1.get(1).unwrap(); 
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_second`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/strings2.rs:75:9
[INFO] [stdout]    |
[INFO] [stdout] 75 |     let mut hello_string = "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]    --> src/strings2.rs:109:9
[INFO] [stdout]     |
[INFO] [stdout] 109 |     let mut hello_str = String::from("hello");
[INFO] [stdout]     |         ----^^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/vectors.rs:189:9
[INFO] [stdout]     |
[INFO] [stdout] 189 |     let slice = &v15[..];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice2`
[INFO] [stdout]    --> src/vectors.rs:191:9
[INFO] [stdout]     |
[INFO] [stdout] 191 |     let slice2 = &mut v15[..]; 
[INFO] [stdout]     |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/iterator.rs:128:9
[INFO] [stdout]     |
[INFO] [stdout] 128 |     let mut iter = a.iter();
[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]   --> src/vectors.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |     let mut first = &mut v3[0];
[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]    --> src/vectors.rs:161:9
[INFO] [stdout]     |
[INFO] [stdout] 161 |     let mut iter = v13.iter_mut();
[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]    --> src/vectors.rs:241:9
[INFO] [stdout]     |
[INFO] [stdout] 241 |     let mut v22 = vec![1,2,3,4,5];
[INFO] [stdout]     |         ----^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 11.88s
[INFO] running `Command { std: "docker" "inspect" "24c3dd0b3c9db9fe285acf5fc1b652dddb6f96d0fc2105cb89268bc8f2bce5a4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "24c3dd0b3c9db9fe285acf5fc1b652dddb6f96d0fc2105cb89268bc8f2bce5a4", kill_on_drop: false }`
[INFO] [stdout] 24c3dd0b3c9db9fe285acf5fc1b652dddb6f96d0fc2105cb89268bc8f2bce5a4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+334963c956d25708feab489a3816ae63f639355d" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d8ab88b2f36856774e1f20a2d93c1ade1fef06131eb3321f8e6070bf767cda8e
[INFO] running `Command { std: "docker" "start" "-a" "d8ab88b2f36856774e1f20a2d93c1ade1fef06131eb3321f8e6070bf767cda8e", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust-random v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]  --> src/problems/cat.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::collections::HashMap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]  --> src/strings.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let hello = String::from("Hello"); //immutable string
[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: `hello_slice`
[INFO] [stdout]   --> src/strings.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let hello_slice = &mut hello[0..5];
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_hello_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word_slice`
[INFO] [stdout]   --> src/strings.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let word_slice = &mut hello[7..];
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_word_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `reverse`
[INFO] [stdout]   --> src/strings.rs:60:9
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let reverse = hello.chars().rev().collect::<String>();
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_reverse`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello_world_string`
[INFO] [stdout]   --> src/strings2.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let hello_world_string = hello_string + &world_string; // It takes ownership of hello_string and returns it back    
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_hello_world_string`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_str`
[INFO] [stdout]    --> src/strings2.rs:100:9
[INFO] [stdout]     |
[INFO] [stdout] 100 |     let new_str = hello_str.push('o');
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_str`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_str2`
[INFO] [stdout]    --> src/strings2.rs:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     let new_str2 = hello_str.push_str(", World");
[INFO] [stdout]     |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_str2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first`
[INFO] [stdout]    --> src/strings2.rs:111:9
[INFO] [stdout]     |
[INFO] [stdout] 111 |     let first = &hello_str[0..1];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_first`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `second`
[INFO] [stdout]    --> src/strings2.rs:113:9
[INFO] [stdout]     |
[INFO] [stdout] 113 |     let second = &hello_str[1..2];
[INFO] [stdout]     |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_second`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/strings2.rs:69:9
[INFO] [stdout]    |
[INFO] [stdout] 69 |     let mut hello_string = "Hello".to_string();
[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]   --> src/strings2.rs:75:9
[INFO] [stdout]    |
[INFO] [stdout] 75 |     let mut hello_string = "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]    --> src/strings2.rs:109:9
[INFO] [stdout]     |
[INFO] [stdout] 109 |     let mut hello_str = String::from("hello");
[INFO] [stdout]     |         ----^^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::iter`
[INFO] [stdout]  --> src/iterator.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::iter;
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `second`
[INFO] [stdout]   --> src/vectors.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let second = v1.get(1).unwrap(); 
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_second`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]    --> src/vectors.rs:189:9
[INFO] [stdout]     |
[INFO] [stdout] 189 |     let slice = &v15[..];
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice2`
[INFO] [stdout]    --> src/vectors.rs:191:9
[INFO] [stdout]     |
[INFO] [stdout] 191 |     let slice2 = &mut v15[..]; 
[INFO] [stdout]     |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_slice2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iter`
[INFO] [stdout]    --> src/iterator.rs:128:13
[INFO] [stdout]     |
[INFO] [stdout] 128 |     let mut iter = a.iter();
[INFO] [stdout]     |             ^^^^ help: if this is intentional, prefix it with an underscore: `_iter`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/vectors.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |     let mut first = &mut v3[0];
[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]    --> src/vectors.rs:161:9
[INFO] [stdout]     |
[INFO] [stdout] 161 |     let mut iter = v13.iter_mut();
[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]    --> src/vectors.rs:241:9
[INFO] [stdout]     |
[INFO] [stdout] 241 |     let mut v22 = vec![1,2,3,4,5];
[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]    --> src/iterator.rs:128:9
[INFO] [stdout]     |
[INFO] [stdout] 128 |     let mut iter = a.iter();
[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] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.92s
[INFO] running `Command { std: "docker" "inspect" "d8ab88b2f36856774e1f20a2d93c1ade1fef06131eb3321f8e6070bf767cda8e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d8ab88b2f36856774e1f20a2d93c1ade1fef06131eb3321f8e6070bf767cda8e", kill_on_drop: false }`
[INFO] [stdout] d8ab88b2f36856774e1f20a2d93c1ade1fef06131eb3321f8e6070bf767cda8e
