[INFO] cloning repository https://github.com/Beskhue/advent-of-code-2018
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Beskhue/advent-of-code-2018" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBeskhue%2Fadvent-of-code-2018", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBeskhue%2Fadvent-of-code-2018'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 4045854c098ce940f65b84fdde7c61aeabcf381b
[INFO] checking Beskhue/advent-of-code-2018 against try#3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f for pr-87248
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBeskhue%2Fadvent-of-code-2018" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Beskhue/advent-of-code-2018 on toolchain 3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Beskhue/advent-of-code-2018
[INFO] finished tweaking git repo https://github.com/Beskhue/advent-of-code-2018
[INFO] tweaked toml for git repo https://github.com/Beskhue/advent-of-code-2018 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/Beskhue/advent-of-code-2018 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded euclid v0.19.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f" "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] afbab32e7d5aa2baae1d163777a6477c5a8b1a6e5c8ecf491c25b0850cfa361b
[INFO] running `Command { std: "docker" "start" "-a" "afbab32e7d5aa2baae1d163777a6477c5a8b1a6e5c8ecf491c25b0850cfa361b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "afbab32e7d5aa2baae1d163777a6477c5a8b1a6e5c8ecf491c25b0850cfa361b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "afbab32e7d5aa2baae1d163777a6477c5a8b1a6e5c8ecf491c25b0850cfa361b", kill_on_drop: false }`
[INFO] [stdout] afbab32e7d5aa2baae1d163777a6477c5a8b1a6e5c8ecf491c25b0850cfa361b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 17a1a517986f1fa8058dee552ced93222142107c0cb57e190748ad3c26d8217b
[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" "17a1a517986f1fa8058dee552ced93222142107c0cb57e190748ad3c26d8217b", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.44
[INFO] [stderr]    Compiling num-traits v0.2.6
[INFO] [stderr]     Checking cfg-if v0.1.6
[INFO] [stderr]     Checking lazy_static v1.2.0
[INFO] [stderr]     Checking maplit v1.0.1
[INFO] [stderr]    Compiling memchr v2.1.1
[INFO] [stderr]     Checking regex-syntax v0.6.4
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking euclid v0.19.3
[INFO] [stderr]     Checking aho-corasick v0.6.9
[INFO] [stderr]     Checking regex v1.1.0
[INFO] [stderr]     Checking advent_of_code_2018 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december16.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december05.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december13.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december13.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december21.rs:6:45
[INFO] [stdout]   |
[INFO] [stdout] 6 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december04.rs:5:45
[INFO] [stdout]   |
[INFO] [stdout] 5 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december06.rs:6:45
[INFO] [stdout]   |
[INFO] [stdout] 6 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december15.rs:7:45
[INFO] [stdout]   |
[INFO] [stdout] 7 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/december20.rs:13:45
[INFO] [stdout]    |
[INFO] [stdout] 13 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]    |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december08.rs:3:45
[INFO] [stdout]   |
[INFO] [stdout] 3 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december10.rs:8:45
[INFO] [stdout]   |
[INFO] [stdout] 8 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: panic message is not a string literal
[INFO] [stdout]   --> src/december20.rs:84:37
[INFO] [stdout]    |
[INFO] [stdout] 84 |                         _ => panic!(format!("Unexpected literal {}", c)),
[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]    = note: the panic!() macro supports formatting, so there's no need for the format!() macro here
[INFO] [stdout] help: remove the `format!(..)` macro call
[INFO] [stdout]    |
[INFO] [stdout] 84 |                         _ => panic!("Unexpected literal {}", c),
[INFO] [stdout]    |                                    --                        --
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december03.rs:7:45
[INFO] [stdout]   |
[INFO] [stdout] 7 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/december20.rs:13:45
[INFO] [stdout]    |
[INFO] [stdout] 13 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]    |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]   --> src/december20.rs:84:37
[INFO] [stdout]    |
[INFO] [stdout] 84 |                         _ => panic!(format!("Unexpected literal {}", c)),
[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]    = note: the panic!() macro supports formatting, so there's no need for the format!() macro here
[INFO] [stdout] help: remove the `format!(..)` macro call
[INFO] [stdout]    |
[INFO] [stdout] 84 |                         _ => panic!("Unexpected literal {}", c),
[INFO] [stdout]    |                                    --                        --
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december17.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december08.rs:3:45
[INFO] [stdout]   |
[INFO] [stdout] 3 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december04.rs:5:45
[INFO] [stdout]   |
[INFO] [stdout] 5 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december12.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december25.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december07.rs:7:45
[INFO] [stdout]   |
[INFO] [stdout] 7 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/december07.rs:45:73
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn work(deps: &HashMap<char, Step>, num_workers: usize, step_duration: &Fn(char) -> i32) -> (String, i32) {
[INFO] [stdout]    |                                                                         ^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Fn(char) -> i32`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december19.rs:6:45
[INFO] [stdout]   |
[INFO] [stdout] 6 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december23.rs:6:45
[INFO] [stdout]   |
[INFO] [stdout] 6 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december18.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december09.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december06.rs:6:45
[INFO] [stdout]   |
[INFO] [stdout] 6 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december10.rs:8:45
[INFO] [stdout]   |
[INFO] [stdout] 8 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december07.rs:7:45
[INFO] [stdout]   |
[INFO] [stdout] 7 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/december07.rs:45:73
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn work(deps: &HashMap<char, Step>, num_workers: usize, step_duration: &Fn(char) -> i32) -> (String, i32) {
[INFO] [stdout]    |                                                                         ^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Fn(char) -> i32`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december12.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `conserve_momentum`
[INFO] [stdout]   --> src/december10.rs:27:4
[INFO] [stdout]    |
[INFO] [stdout] 27 | fn conserve_momentum(sky: &mut Sky) -> (Sky, i32) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december16.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december22.rs:6:45
[INFO] [stdout]   |
[INFO] [stdout] 6 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december03.rs:7:45
[INFO] [stdout]   |
[INFO] [stdout] 7 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december18.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december24.rs:5:45
[INFO] [stdout]   |
[INFO] [stdout] 5 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december21.rs:6:45
[INFO] [stdout]   |
[INFO] [stdout] 6 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december19.rs:6:45
[INFO] [stdout]   |
[INFO] [stdout] 6 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: function is never used: `lines_from_file`
[INFO] [stdout]  --> src/utils.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn lines_from_file<P>(filename: P) -> io::Result<Vec<String>>
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december09.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december23.rs:6:45
[INFO] [stdout]   |
[INFO] [stdout] 6 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december05.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december25.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december24.rs:5:45
[INFO] [stdout]   |
[INFO] [stdout] 5 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december22.rs:6:45
[INFO] [stdout]   |
[INFO] [stdout] 6 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december17.rs:4:45
[INFO] [stdout]   |
[INFO] [stdout] 4 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `lines_from_file`
[INFO] [stdout]  --> src/utils.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | pub fn lines_from_file<P>(filename: P) -> io::Result<Vec<String>>
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/december15.rs:7:45
[INFO] [stdout]   |
[INFO] [stdout] 7 | type Result<T> = std::result::Result<T, Box<std::error::Error>>;
[INFO] [stdout]   |                                             ^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn std::error::Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2015) 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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 13.29s
[INFO] running `Command { std: "docker" "inspect" "17a1a517986f1fa8058dee552ced93222142107c0cb57e190748ad3c26d8217b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "17a1a517986f1fa8058dee552ced93222142107c0cb57e190748ad3c26d8217b", kill_on_drop: false }`
[INFO] [stdout] 17a1a517986f1fa8058dee552ced93222142107c0cb57e190748ad3c26d8217b