[INFO] updating cached repository https://github.com/halcyon/rust_tut
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 558bf4aae326605a6934155e7faf29e8747627d9
[INFO] testing halcyon/rust_tut against 1.45.2 for beta-1.46-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhalcyon%2Frust_tut" "/workspace/builds/worker-14/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-14/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/halcyon/rust_tut on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/halcyon/rust_tut
[INFO] finished tweaking git repo https://github.com/halcyon/rust_tut
[INFO] tweaked toml for git repo https://github.com/halcyon/rust_tut written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] crate git repo https://github.com/halcyon/rust_tut already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a165a3abbb7ea0c14f40c051a33b42f51bbfb8bfd0381e9a5837cfa4a41de06e
[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" "a165a3abbb7ea0c14f40c051a33b42f51bbfb8bfd0381e9a5837cfa4a41de06e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a165a3abbb7ea0c14f40c051a33b42f51bbfb8bfd0381e9a5837cfa4a41de06e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a165a3abbb7ea0c14f40c051a33b42f51bbfb8bfd0381e9a5837cfa4a41de06e", kill_on_drop: false }`
[INFO] [stdout] a165a3abbb7ea0c14f40c051a33b42f51bbfb8bfd0381e9a5837cfa4a41de06e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 55ec2c380c9137e027444ac0542ee31209b2bd449e753a80e445dae8e03188bf
[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" "55ec2c380c9137e027444ac0542ee31209b2bd449e753a80e445dae8e03188bf", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_tut v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `u16`, `u32`, `u64`, `u8`
[INFO] [stdout]  --> src/main.rs:1:30
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{i8, i16, i32, i64, u8, u16, u32, u64, isize, usize, f32, f64};
[INFO] [stdout]   |                              ^^  ^^^  ^^^  ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/main.rs:62:8
[INFO] [stdout]    |
[INFO] [stdout] 62 |     if (age_old == 5) {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/main.rs:78:23
[INFO] [stdout]    |
[INFO] [stdout] 78 |     let can_vote = if (age_old >= 18) { true } else { false };
[INFO] [stdout]    |                       ^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/main.rs:85:12
[INFO] [stdout]    |
[INFO] [stdout] 85 |         if ((x % 2) == 0) {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/main.rs:90:12
[INFO] [stdout]    |
[INFO] [stdout] 90 |         if (x > 10) {
[INFO] [stdout]    |            ^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num`
[INFO] [stdout]  --> src/main.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let num = 10;
[INFO] [stdout]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_num`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f_name`
[INFO] [stdout]   --> src/main.rs:34:10
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let (f_name, l_name) = ("Derek", "Banas");
[INFO] [stdout]    |          ^^^^^^ help: if this is intentional, prefix it with an underscore: `_f_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `l_name`
[INFO] [stdout]   --> src/main.rs:34:18
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let (f_name, l_name) = ("Derek", "Banas");
[INFO] [stdout]    |                  ^^^^^^ help: if this is intentional, prefix it with an underscore: `_l_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/main.rs:116:9
[INFO] [stdout]     |
[INFO] [stdout] 116 |     let count = rand_string.chars().count();
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_count`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut age: i32 = 40;
[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/main.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let mut neg_4 = -4i32;
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 11 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.15s
[INFO] running `Command { std: "docker" "inspect" "55ec2c380c9137e027444ac0542ee31209b2bd449e753a80e445dae8e03188bf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "55ec2c380c9137e027444ac0542ee31209b2bd449e753a80e445dae8e03188bf", kill_on_drop: false }`
[INFO] [stdout] 55ec2c380c9137e027444ac0542ee31209b2bd449e753a80e445dae8e03188bf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dd798d266f4f8b2f58887f5a9934d235ea8dcc8b5c90b6437d96ad66ebb78752
[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" "dd798d266f4f8b2f58887f5a9934d235ea8dcc8b5c90b6437d96ad66ebb78752", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_tut v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `u16`, `u32`, `u64`, `u8`
[INFO] [stdout]  --> src/main.rs:1:30
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{i8, i16, i32, i64, u8, u16, u32, u64, isize, usize, f32, f64};
[INFO] [stdout]   |                              ^^  ^^^  ^^^  ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/main.rs:62:8
[INFO] [stdout]    |
[INFO] [stdout] 62 |     if (age_old == 5) {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/main.rs:78:23
[INFO] [stdout]    |
[INFO] [stdout] 78 |     let can_vote = if (age_old >= 18) { true } else { false };
[INFO] [stdout]    |                       ^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/main.rs:85:12
[INFO] [stdout]    |
[INFO] [stdout] 85 |         if ((x % 2) == 0) {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/main.rs:90:12
[INFO] [stdout]    |
[INFO] [stdout] 90 |         if (x > 10) {
[INFO] [stdout]    |            ^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `num`
[INFO] [stdout]  --> src/main.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let num = 10;
[INFO] [stdout]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_num`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f_name`
[INFO] [stdout]   --> src/main.rs:34:10
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let (f_name, l_name) = ("Derek", "Banas");
[INFO] [stdout]    |          ^^^^^^ help: if this is intentional, prefix it with an underscore: `_f_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `l_name`
[INFO] [stdout]   --> src/main.rs:34:18
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let (f_name, l_name) = ("Derek", "Banas");
[INFO] [stdout]    |                  ^^^^^^ help: if this is intentional, prefix it with an underscore: `_l_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/main.rs:116:9
[INFO] [stdout]     |
[INFO] [stdout] 116 |     let count = rand_string.chars().count();
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_count`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut age: i32 = 40;
[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/main.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |     let mut neg_4 = -4i32;
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.79s
[INFO] [stdout] warning: 11 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "dd798d266f4f8b2f58887f5a9934d235ea8dcc8b5c90b6437d96ad66ebb78752", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dd798d266f4f8b2f58887f5a9934d235ea8dcc8b5c90b6437d96ad66ebb78752", kill_on_drop: false }`
[INFO] [stdout] dd798d266f4f8b2f58887f5a9934d235ea8dcc8b5c90b6437d96ad66ebb78752
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "test" "--frozen", 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] 8d52d2777cfe80923c26c728c92e677052f5040d69759820904c11d1e0c296b9
[INFO] running `Command { std: "docker" "start" "-a" "8d52d2777cfe80923c26c728c92e677052f5040d69759820904c11d1e0c296b9", kill_on_drop: false }`
[INFO] [stderr] warning: unused imports: `u16`, `u32`, `u64`, `u8`
[INFO] [stderr]  --> src/main.rs:1:30
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::{i8, i16, i32, i64, u8, u16, u32, u64, isize, usize, f32, f64};
[INFO] [stderr]   |                              ^^  ^^^  ^^^  ^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `if` condition
[INFO] [stderr]   --> src/main.rs:62:8
[INFO] [stderr]    |
[INFO] [stderr] 62 |     if (age_old == 5) {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `if` condition
[INFO] [stderr]   --> src/main.rs:78:23
[INFO] [stderr]    |
[INFO] [stderr] 78 |     let can_vote = if (age_old >= 18) { true } else { false };
[INFO] [stderr]    |                       ^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `if` condition
[INFO] [stderr]   --> src/main.rs:85:12
[INFO] [stderr]    |
[INFO] [stderr] 85 |         if ((x % 2) == 0) {
[INFO] [stderr]    |            ^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `if` condition
[INFO] [stderr]   --> src/main.rs:90:12
[INFO] [stderr]    |
[INFO] [stderr] 90 |         if (x > 10) {
[INFO] [stderr]    |            ^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]  --> src/main.rs:8:9
[INFO] [stderr]   |
[INFO] [stderr] 8 |     let num = 10;
[INFO] [stderr]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_num`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f_name`
[INFO] [stderr]   --> src/main.rs:34:10
[INFO] [stderr]    |
[INFO] [stderr] 34 |     let (f_name, l_name) = ("Derek", "Banas");
[INFO] [stderr]    |          ^^^^^^ help: if this is intentional, prefix it with an underscore: `_f_name`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `l_name`
[INFO] [stderr]   --> src/main.rs:34:18
[INFO] [stderr]    |
[INFO] [stderr] 34 |     let (f_name, l_name) = ("Derek", "Banas");
[INFO] [stderr]    |                  ^^^^^^ help: if this is intentional, prefix it with an underscore: `_l_name`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `count`
[INFO] [stderr]    --> src/main.rs:116:9
[INFO] [stderr]     |
[INFO] [stderr] 116 |     let count = rand_string.chars().count();
[INFO] [stderr]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_count`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:10:9
[INFO] [stderr]    |
[INFO] [stderr] 10 |     let mut age: i32 = 40;
[INFO] [stderr]    |         ----^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:52:9
[INFO] [stderr]    |
[INFO] [stderr] 52 |     let mut neg_4 = -4i32;
[INFO] [stderr]    |         ----^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: 11 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.04s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/rust_tut-235a89f3aa03c6ad
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "8d52d2777cfe80923c26c728c92e677052f5040d69759820904c11d1e0c296b9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8d52d2777cfe80923c26c728c92e677052f5040d69759820904c11d1e0c296b9", kill_on_drop: false }`
[INFO] [stdout] 8d52d2777cfe80923c26c728c92e677052f5040d69759820904c11d1e0c296b9