[INFO] cloning repository https://github.com/VioletOh/rust_playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/VioletOh/rust_playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVioletOh%2Frust_playground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVioletOh%2Frust_playground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ace208a08ab84deeee6cdc0d4b4d0f3207d1fa5c
[INFO] checking VioletOh/rust_playground against try#b047d5f4496a7526d91d0dddea494c05853f2a7b for pr-122661-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVioletOh%2Frust_playground" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/VioletOh/rust_playground
[INFO] finished tweaking git repo https://github.com/VioletOh/rust_playground
[INFO] tweaked toml for git repo https://github.com/VioletOh/rust_playground written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/VioletOh/rust_playground on toolchain b047d5f4496a7526d91d0dddea494c05853f2a7b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b047d5f4496a7526d91d0dddea494c05853f2a7b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/VioletOh/rust_playground 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" "+b047d5f4496a7526d91d0dddea494c05853f2a7b" "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-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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:cf8efcab8866f2cf4285301c7418e2f4f2a9b088c91ba69c40d5b659f81557f7" "/opt/rustwide/cargo-home/bin/cargo" "+b047d5f4496a7526d91d0dddea494c05853f2a7b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 92b63c36650ebd8999121df88aeab954cd4b841cd935d2ad2db999d1b6d0d20a
[INFO] running `Command { std: "docker" "start" "-a" "92b63c36650ebd8999121df88aeab954cd4b841cd935d2ad2db999d1b6d0d20a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "92b63c36650ebd8999121df88aeab954cd4b841cd935d2ad2db999d1b6d0d20a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "92b63c36650ebd8999121df88aeab954cd4b841cd935d2ad2db999d1b6d0d20a", kill_on_drop: false }`
[INFO] [stdout] 92b63c36650ebd8999121df88aeab954cd4b841cd935d2ad2db999d1b6d0d20a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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:cf8efcab8866f2cf4285301c7418e2f4f2a9b088c91ba69c40d5b659f81557f7" "/opt/rustwide/cargo-home/bin/cargo" "+b047d5f4496a7526d91d0dddea494c05853f2a7b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 28abc5f5125d866f20aa5d51f6fcf76cfe860bd105b7c28a566a0b6d984b03d2
[INFO] running `Command { std: "docker" "start" "-a" "28abc5f5125d866f20aa5d51f6fcf76cfe860bd105b7c28a566a0b6d984b03d2", kill_on_drop: false }`
[INFO] [stderr]     Checking hello_world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]    --> src/main.rs:134:5
[INFO] [stdout]     |
[INFO] [stdout] 134 |     ((1.8 * temp as f64) + 32 as f64)
[INFO] [stdout]     |     ^                               ^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 134 -     ((1.8 * temp as f64) + 32 as f64)
[INFO] [stdout] 134 +     (1.8 * temp as f64) + 32 as f64
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]    --> src/main.rs:134:5
[INFO] [stdout]     |
[INFO] [stdout] 134 |     ((1.8 * temp as f64) + 32 as f64)
[INFO] [stdout]     |     ^                               ^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout] 134 -     ((1.8 * temp as f64) + 32 as f64)
[INFO] [stdout] 134 +     (1.8 * temp as f64) + 32 as f64
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: `(usize, &char)` doesn't implement `std::fmt::Display`
[INFO] [stdout]   --> src/main.rs:83:32
[INFO] [stdout]    |
[INFO] [stdout] 83 |         println!("item is {}", item);
[INFO] [stdout]    |                           --   ^^^^ `(usize, &char)` cannot be formatted with the default formatter
[INFO] [stdout]    |                           |
[INFO] [stdout]    |                           required by this formatting parameter
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `std::fmt::Display` is not implemented for `(usize, &char)`
[INFO] [stdout]    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
[INFO] [stdout]    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: `(usize, &char)` doesn't implement `std::fmt::Display`
[INFO] [stdout]   --> src/main.rs:83:32
[INFO] [stdout]    |
[INFO] [stdout] 83 |         println!("item is {}", item);
[INFO] [stdout]    |                           --   ^^^^ `(usize, &char)` cannot be formatted with the default formatter
[INFO] [stdout]    |                           |
[INFO] [stdout]    |                           required by this formatting parameter
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `std::fmt::Display` is not implemented for `(usize, &char)`
[INFO] [stdout]    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
[INFO] [stdout]    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]    --> src/main.rs:143:5
[INFO] [stdout]     |
[INFO] [stdout] 142 |     return (x, x * x);
[INFO] [stdout]     |     ----------------- any code following this expression is unreachable
[INFO] [stdout] 143 |     println!("End of function");
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout]     = note: this warning originates in the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]    --> src/main.rs:143:5
[INFO] [stdout]     |
[INFO] [stdout] 142 |     return (x, x * x);
[INFO] [stdout]     |     ----------------- any code following this expression is unreachable
[INFO] [stdout] 143 |     println!("End of function");
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout]     = note: this warning originates in the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/main.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let y: u8 = 255; // initializing it to 1000 wouldn't work since maximum possible val is 255
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let z = 10.0;
[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]   --> src/main.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let y: u8 = 255; // initializing it to 1000 wouldn't work since maximum possible val is 255
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let z = 10.0;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let mut x: u8 = 255;
[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:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let mut x: u8 = 255;
[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: `a`
[INFO] [stdout]    --> src/main.rs:176:10
[INFO] [stdout]     |
[INFO] [stdout] 176 |     let (a, b, c) = stuff;
[INFO] [stdout]     |          ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]    --> src/main.rs:176:16
[INFO] [stdout]     |
[INFO] [stdout] 176 |     let (a, b, c) = stuff;
[INFO] [stdout]     |                ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `garage`
[INFO] [stdout]    --> src/main.rs:185:9
[INFO] [stdout]     |
[INFO] [stdout] 185 |     let garage = [[[0; 100]; 20]; 5]; // Three dimensinal array
[INFO] [stdout]     |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_garage`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/main.rs:176:10
[INFO] [stdout]     |
[INFO] [stdout] 176 |     let (a, b, c) = stuff;
[INFO] [stdout]     |          ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]    --> src/main.rs:176:16
[INFO] [stdout]     |
[INFO] [stdout] 176 |     let (a, b, c) = stuff;
[INFO] [stdout]     |                ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `garage`
[INFO] [stdout]    --> src/main.rs:185:9
[INFO] [stdout]     |
[INFO] [stdout] 185 |     let garage = [[[0; 100]; 20]; 5]; // Three dimensinal array
[INFO] [stdout]     |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_garage`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `hello_world` (bin "hello_world") due to 1 previous error; 8 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `hello_world` (bin "hello_world" test) due to 1 previous error; 8 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "28abc5f5125d866f20aa5d51f6fcf76cfe860bd105b7c28a566a0b6d984b03d2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "28abc5f5125d866f20aa5d51f6fcf76cfe860bd105b7c28a566a0b6d984b03d2", kill_on_drop: false }`
[INFO] [stdout] 28abc5f5125d866f20aa5d51f6fcf76cfe860bd105b7c28a566a0b6d984b03d2