[INFO] cloning repository https://github.com/psatomas/data-types
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/psatomas/data-types" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpsatomas%2Fdata-types", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpsatomas%2Fdata-types'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 722c4d8b1fa63352dfec992edeef84b8d59a35d5
[INFO] checking psatomas/data-types against master#f8f6997469237299c1d60814c7b9828602a1f8e4 for pr-143808
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpsatomas%2Fdata-types" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/psatomas/data-types
[INFO] finished tweaking git repo https://github.com/psatomas/data-types
[INFO] tweaked toml for git repo https://github.com/psatomas/data-types written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/psatomas/data-types on toolchain f8f6997469237299c1d60814c7b9828602a1f8e4
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f8f6997469237299c1d60814c7b9828602a1f8e4" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/psatomas/data-types 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" "+f8f6997469237299c1d60814c7b9828602a1f8e4" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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:cf8efcab8866f2cf4285301c7418e2f4f2a9b088c91ba69c40d5b659f81557f7" "/opt/rustwide/cargo-home/bin/cargo" "+f8f6997469237299c1d60814c7b9828602a1f8e4" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 86896bc713c0f31525544010bf52d4f576ef4f5c30eba59f61c256c35cbe36d0
[INFO] running `Command { std: "docker" "start" "-a" "86896bc713c0f31525544010bf52d4f576ef4f5c30eba59f61c256c35cbe36d0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "86896bc713c0f31525544010bf52d4f576ef4f5c30eba59f61c256c35cbe36d0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "86896bc713c0f31525544010bf52d4f576ef4f5c30eba59f61c256c35cbe36d0", kill_on_drop: false }`
[INFO] [stdout] 86896bc713c0f31525544010bf52d4f576ef4f5c30eba59f61c256c35cbe36d0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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:cf8efcab8866f2cf4285301c7418e2f4f2a9b088c91ba69c40d5b659f81557f7" "/opt/rustwide/cargo-home/bin/cargo" "+f8f6997469237299c1d60814c7b9828602a1f8e4" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 49c76b98cb8edbfba862fbfc7a0bb8fcade8bf465cef66f671691766e18ae7aa
[INFO] running `Command { std: "docker" "start" "-a" "49c76b98cb8edbfba862fbfc7a0bb8fcade8bf465cef66f671691766e18ae7aa", kill_on_drop: false }`
[INFO] [stderr]     Checking data-types v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `seasons`
[INFO] [stdout]  --> src/bin/the_display_trait.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let seasons = ["Spring", "Summer", "Fall", "Winter"];
[INFO] [stdout]   |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_seasons`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `month_days`
[INFO] [stdout]  --> src/bin/intro_to_generics.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let month_days: std::ops::Range<i32> = 1..31;
[INFO] [stdout]   |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_month_days`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `letters`
[INFO] [stdout]  --> src/bin/intro_to_generics.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let letters: std::ops::Range<char> = 'b'..'f';
[INFO] [stdout]   |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_letters`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `miles_away_i8`
[INFO] [stdout]  --> src/bin/casting_types_with_the_as_keyword.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let miles_away_i8 = miles_away as i8;
[INFO] [stdout]   |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_miles_away_i8`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `miles_away_u8`
[INFO] [stdout]  --> src/bin/casting_types_with_the_as_keyword.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let miles_away_u8: u8 = miles_away as u8;
[INFO] [stdout]   |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_miles_away_u8`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `miles_away_f32`
[INFO] [stdout]  --> src/bin/casting_types_with_the_as_keyword.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let miles_away_f32 = miles_away as f32;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_miles_away_f32`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `days`
[INFO] [stdout]  --> src/bin/the_usize_and_isize_types.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let days: usize = 55;
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_days`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `years`
[INFO] [stdout]  --> src/bin/the_usize_and_isize_types.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let years: isize = -15_000;
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_years`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `days`
[INFO] [stdout]  --> src/bin/the_usize_and_isize_types.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let days: usize = 55;
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_days`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `years`
[INFO] [stdout]  --> src/bin/the_usize_and_isize_types.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let years: isize = -15_000;
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_years`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sixteen_bit_signed`
[INFO] [stdout]  --> src/bin/using_underscore_as_visual_separator_for_numbers.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let sixteen_bit_signed: i16 = 32_500;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sixteen_bit_signed`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sixteen_bit_signed`
[INFO] [stdout]  --> src/bin/using_underscore_as_visual_separator_for_numbers.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let sixteen_bit_signed: i16 = -3_2_500;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sixteen_bit_signed`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sixteen_bit_signed`
[INFO] [stdout]  --> src/bin/using_underscore_as_visual_separator_for_numbers.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let sixteen_bit_signed: i16 = -3_2_5_00;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sixteen_bit_signed`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `seasons`
[INFO] [stdout]  --> src/bin/the_display_trait.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let seasons = ["Spring", "Summer", "Fall", "Winter"];
[INFO] [stdout]   |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_seasons`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `miles_away_i8`
[INFO] [stdout]  --> src/bin/casting_types_with_the_as_keyword.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let miles_away_i8 = miles_away as i8;
[INFO] [stdout]   |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_miles_away_i8`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `miles_away_u8`
[INFO] [stdout]  --> src/bin/casting_types_with_the_as_keyword.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let miles_away_u8: u8 = miles_away as u8;
[INFO] [stdout]   |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_miles_away_u8`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `miles_away_f32`
[INFO] [stdout]  --> src/bin/casting_types_with_the_as_keyword.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let miles_away_f32 = miles_away as f32;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_miles_away_f32`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `is_acceptable_coffe`
[INFO] [stdout]   --> src/main.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let is_acceptable_coffe = with_milk || with_sugar;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_is_acceptable_coffe`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `numbers`
[INFO] [stdout]  --> src/bin/the_array_type.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let numbers: [i32; 6] = [4, 8, 15, 16, 23, 42];
[INFO] [stdout]   |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_numbers`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `currency_rates`
[INFO] [stdout]  --> src/bin/the_array_type.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let currency_rates: [f64; 0] = [];
[INFO] [stdout]   |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_currency_rates`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sixteen_bit_signed`
[INFO] [stdout]  --> src/bin/integers.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let sixteen_bit_signed: i16 = -32500;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sixteen_bit_signed`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sixteen_bit_unsigned`
[INFO] [stdout]  --> src/bin/integers.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let sixteen_bit_unsigned: u16 = 64000;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sixteen_bit_unsigned`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `thirty_two_bit_signed`
[INFO] [stdout]  --> src/bin/integers.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let thirty_two_bit_signed: i32 = -2147483648;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_thirty_two_bit_signed`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `thirty_two_bit_unsigned`
[INFO] [stdout]  --> src/bin/integers.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let thirty_two_bit_unsigned: u32 = 4294967295;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_thirty_two_bit_unsigned`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_value`
[INFO] [stdout]  --> src/bin/integers.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let some_value = 20u16;
[INFO] [stdout]   |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_value`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sixteen_bit_signed`
[INFO] [stdout]  --> src/bin/integers.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let sixteen_bit_signed: i16 = -32500;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sixteen_bit_signed`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sixteen_bit_unsigned`
[INFO] [stdout]  --> src/bin/integers.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let sixteen_bit_unsigned: u16 = 64000;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sixteen_bit_unsigned`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `thirty_two_bit_signed`
[INFO] [stdout]  --> src/bin/integers.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let thirty_two_bit_signed: i32 = -2147483648;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_thirty_two_bit_signed`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `thirty_two_bit_unsigned`
[INFO] [stdout]  --> src/bin/integers.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let thirty_two_bit_unsigned: u32 = 4294967295;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_thirty_two_bit_unsigned`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_value`
[INFO] [stdout]  --> src/bin/integers.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let some_value = 20u16;
[INFO] [stdout]   |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_value`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `is_acceptable_coffe`
[INFO] [stdout]   --> src/main.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let is_acceptable_coffe = with_milk || with_sugar;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_is_acceptable_coffe`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sixteen_bit_signed`
[INFO] [stdout]  --> src/bin/using_underscore_as_visual_separator_for_numbers.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let sixteen_bit_signed: i16 = 32_500;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sixteen_bit_signed`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sixteen_bit_signed`
[INFO] [stdout]  --> src/bin/using_underscore_as_visual_separator_for_numbers.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let sixteen_bit_signed: i16 = -3_2_500;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sixteen_bit_signed`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `sixteen_bit_signed`
[INFO] [stdout]  --> src/bin/using_underscore_as_visual_separator_for_numbers.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let sixteen_bit_signed: i16 = -3_2_5_00;
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_sixteen_bit_signed`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `numbers`
[INFO] [stdout]  --> src/bin/the_array_type.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let numbers: [i32; 6] = [4, 8, 15, 16, 23, 42];
[INFO] [stdout]   |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_numbers`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `currency_rates`
[INFO] [stdout]  --> src/bin/the_array_type.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let currency_rates: [f64; 0] = [];
[INFO] [stdout]   |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_currency_rates`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `month_days`
[INFO] [stdout]  --> src/bin/intro_to_generics.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let month_days: std::ops::Range<i32> = 1..31;
[INFO] [stdout]   |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_month_days`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `letters`
[INFO] [stdout]  --> src/bin/intro_to_generics.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let letters: std::ops::Range<char> = 'b'..'f';
[INFO] [stdout]   |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_letters`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.01s
[INFO] running `Command { std: "docker" "inspect" "49c76b98cb8edbfba862fbfc7a0bb8fcade8bf465cef66f671691766e18ae7aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "49c76b98cb8edbfba862fbfc7a0bb8fcade8bf465cef66f671691766e18ae7aa", kill_on_drop: false }`
[INFO] [stdout] 49c76b98cb8edbfba862fbfc7a0bb8fcade8bf465cef66f671691766e18ae7aa