[INFO] cloning repository https://github.com/hulthe/aoc_2018
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/hulthe/aoc_2018" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhulthe%2Faoc_2018", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhulthe%2Faoc_2018'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9c115ce01e7bb956d97725df75e5fd43b351c2c7
[INFO] testing hulthe/aoc_2018 against 1.54.0 for beta-1.55-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhulthe%2Faoc_2018" "/workspace/builds/worker-86/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-86/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/hulthe/aoc_2018 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/hulthe/aoc_2018
[INFO] finished tweaking git repo https://github.com/hulthe/aoc_2018
[INFO] tweaked toml for git repo https://github.com/hulthe/aoc_2018 written to /workspace/builds/worker-86/source/Cargo.toml
[INFO] crate git repo https://github.com/hulthe/aoc_2018 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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-86/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/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" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f184262542c7bdaff9b336ecc3e86c92c695bf153fc2f340fc7b3ef2a1098996
[INFO] running `Command { std: "docker" "start" "-a" "f184262542c7bdaff9b336ecc3e86c92c695bf153fc2f340fc7b3ef2a1098996", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f184262542c7bdaff9b336ecc3e86c92c695bf153fc2f340fc7b3ef2a1098996", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f184262542c7bdaff9b336ecc3e86c92c695bf153fc2f340fc7b3ef2a1098996", kill_on_drop: false }`
[INFO] [stdout] f184262542c7bdaff9b336ecc3e86c92c695bf153fc2f340fc7b3ef2a1098996
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-86/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=warn" "-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" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 886b5771e85995cffee150477b38d96ecffcf938d3098da67440d843ebdc0927
[INFO] running `Command { std: "docker" "start" "-a" "886b5771e85995cffee150477b38d96ecffcf938d3098da67440d843ebdc0927", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.44
[INFO] [stderr]    Compiling cfg-if v0.1.6
[INFO] [stderr]    Compiling lazy_static v1.2.0
[INFO] [stderr]    Compiling rand_core v0.3.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling scopeguard v0.3.3
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]    Compiling proc-macro2 v0.4.24
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling futures v0.1.25
[INFO] [stderr]    Compiling nodrop v0.1.13
[INFO] [stderr]    Compiling memoffset v0.2.1
[INFO] [stderr]    Compiling byteorder v1.2.7
[INFO] [stderr]    Compiling cc v1.0.25
[INFO] [stderr]    Compiling stable_deref_trait v1.1.1
[INFO] [stderr]    Compiling aoc_base v0.1.0 (/opt/rustwide/workdir/aoc_base)
[INFO] [stderr]    Compiling slab v0.4.1
[INFO] [stderr]    Compiling lazycell v1.2.1
[INFO] [stderr]    Compiling pkg-config v0.3.14
[INFO] [stderr]    Compiling either v1.5.0
[INFO] [stderr]    Compiling rayon-core v1.4.1
[INFO] [stderr]    Compiling siphasher v0.2.3
[INFO] [stderr]    Compiling serde v1.0.80
[INFO] [stderr]    Compiling itoa v0.4.3
[INFO] [stderr]    Compiling rayon v1.0.3
[INFO] [stderr]    Compiling num-traits v0.2.6
[INFO] [stderr]    Compiling failure_derive v0.1.3
[INFO] [stderr]    Compiling bitflags v1.0.4
[INFO] [stderr]    Compiling ucd-trie v0.1.1
[INFO] [stderr]    Compiling httparse v1.3.3
[INFO] [stderr]    Compiling matches v0.1.8
[INFO] [stderr]    Compiling rustc-demangle v0.1.9
[INFO] [stderr]    Compiling fnv v1.0.6
[INFO] [stderr]    Compiling openssl v0.10.15
[INFO] [stderr]    Compiling crc32fast v1.1.2
[INFO] [stderr]    Compiling num-integer v0.1.39
[INFO] [stderr]    Compiling unicode-normalization v0.1.7
[INFO] [stderr]    Compiling maplit v1.0.1
[INFO] [stderr]    Compiling unicode-width v0.1.5
[INFO] [stderr]    Compiling regex v1.1.0
[INFO] [stderr]    Compiling ryu v0.2.7
[INFO] [stderr]    Compiling try-lock v0.2.2
[INFO] [stderr]    Compiling indexmap v1.0.2
[INFO] [stderr]    Compiling ucd-util v0.1.3
[INFO] [stderr]    Compiling native-tls v0.2.2
[INFO] [stderr]    Compiling string v0.1.2
[INFO] [stderr]    Compiling utf8-ranges v1.0.2
[INFO] [stderr]    Compiling encoding_rs v0.8.13
[INFO] [stderr]    Compiling safemem v0.3.0
[INFO] [stderr]    Compiling openssl-probe v0.1.2
[INFO] [stderr]    Compiling dtoa v0.4.3
[INFO] [stderr]    Compiling adler32 v1.0.3
[INFO] [stderr]    Compiling strsim v0.7.0
[INFO] [stderr]    Compiling ansi_term v0.11.0
[INFO] [stderr]    Compiling binary-heap-plus v0.1.4
[INFO] [stderr]    Compiling vec_map v0.8.1
[INFO] [stderr]    Compiling hex v0.3.2
[INFO] [stderr]    Compiling xdg v2.2.0
[INFO] [stderr]    Compiling unreachable v1.0.0
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> aoc_base/src/lib.rs:8:46
[INFO] [stdout]   |
[INFO] [stdout] 8 |     fn task_a(input: &str) -> Result<RA, Box<Error>>;
[INFO] [stdout]   |                                              ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[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]  --> aoc_base/src/lib.rs:9:46
[INFO] [stdout]   |
[INFO] [stdout] 9 |     fn task_b(input: &str) -> Result<RB, Box<Error>>;
[INFO] [stdout]   |                                              ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]   = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling aoc_2018_day12 v0.1.0 (/opt/rustwide/workdir/day12)
[INFO] [stderr]    Compiling aoc_2018_day02 v0.1.0 (/opt/rustwide/workdir/day02)
[INFO] [stderr]    Compiling aoc_2018_day10 v0.1.0 (/opt/rustwide/workdir/day10)
[INFO] [stderr]    Compiling aoc_2018_day01 v0.1.0 (/opt/rustwide/workdir/day01)
[INFO] [stderr]    Compiling aoc_2018_day09 v0.1.0 (/opt/rustwide/workdir/day09)
[INFO] [stderr]    Compiling aoc_2018_day08 v0.1.0 (/opt/rustwide/workdir/day08)
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling pest v2.0.2
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> day12/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> day10/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> day09/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling unicase v1.4.2
[INFO] [stderr]    Compiling memchr v2.1.1
[INFO] [stderr]    Compiling unicase v2.2.0
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> day10/src/lib.rs:123:50
[INFO] [stdout]     |
[INFO] [stdout] 123 |     fn task_a(input: &str) -> Result<String, Box<Error>> {
[INFO] [stdout]     |                                                  ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[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]   --> day12/src/lib.rs:92:47
[INFO] [stdout]    |
[INFO] [stdout] 92 |     fn task_a(input: &str) -> Result<i64, Box<Error>> {
[INFO] [stdout]    |                                               ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[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]   --> day12/src/lib.rs:96:47
[INFO] [stdout]    |
[INFO] [stdout] 96 |     fn task_b(input: &str) -> Result<i64, Box<Error>> {
[INFO] [stdout]    |                                               ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[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]    --> day10/src/lib.rs:128:47
[INFO] [stdout]     |
[INFO] [stdout] 128 |     fn task_b(input: &str) -> Result<i32, Box<Error>> {
[INFO] [stdout]     |                                               ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> day09/src/lib.rs:26:59
[INFO] [stdout]    |
[INFO] [stdout] 26 | fn parse_input(input: &str) -> Result<(usize, usize), Box<Error>> {
[INFO] [stdout]    |                                                           ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[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]   --> day09/src/lib.rs:59:49
[INFO] [stdout]    |
[INFO] [stdout] 59 |     fn task_a(input: &str) -> Result<usize, Box<Error>> {
[INFO] [stdout]    |                                                 ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `aoc_2018_day10`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> day02/src/lib.rs:9:48
[INFO] [stdout]   |
[INFO] [stdout] 9 |     fn task_a(inputs: &str) -> Result<i32, Box<Error>> {
[INFO] [stdout]   |                                                ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[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]   --> day02/src/lib.rs:41:48
[INFO] [stdout]    |
[INFO] [stdout] 41 |     fn task_b(ids: &str) -> Result<String, Box<Error>> {
[INFO] [stdout]    |                                                ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[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]   --> day09/src/lib.rs:64:49
[INFO] [stdout]    |
[INFO] [stdout] 64 |     fn task_b(input: &str) -> Result<usize, Box<Error>> {
[INFO] [stdout]    |                                                 ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `std::option::NoneError`
[INFO] [stdout]  --> day08/src/tree.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::option::NoneError;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^ no `NoneError` in `option`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> day08/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> day08/src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(try_trait)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> day08/src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(uniform_paths)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `uniform_paths` has been stable since 1.32.0 and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0283]: type annotations needed
[INFO] [stdout]   --> day02/src/lib.rs:61:34
[INFO] [stdout]    |
[INFO] [stdout] 61 |                     let mut id = String::from(s1.as_ref());
[INFO] [stdout]    |                                  ^^^^^^^^^^^^ cannot infer type for reference `&_`
[INFO] [stdout]    |
[INFO] [stdout]    = note: cannot satisfy `String: From<&_>`
[INFO] [stdout]    = note: required by `from`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0283`.
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> day08/src/lib.rs:13:49
[INFO] [stdout]    |
[INFO] [stdout] 13 |     fn task_a(input: &str) -> Result<usize, Box<Error>> {
[INFO] [stdout]    |                                                 ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[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]   --> day08/src/lib.rs:20:49
[INFO] [stdout]    |
[INFO] [stdout] 20 |     fn task_b(input: &str) -> Result<usize, Box<Error>> {
[INFO] [stdout]    |                                                 ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> day01/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> day01/src/lib.rs:17:47
[INFO] [stdout]    |
[INFO] [stdout] 17 |     fn task_a(input: &str) -> Result<i32, Box<Error>> {
[INFO] [stdout]    |                                               ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[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]   --> day01/src/lib.rs:24:47
[INFO] [stdout]    |
[INFO] [stdout] 24 |     fn task_b(input: &str) -> Result<i32, Box<Error>> {
[INFO] [stdout]    |                                               ^^^^^ help: use `dyn`: `dyn Error`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used on `Result`s, not `Option`s, in a method that returns `Result`
[INFO] [stdout]   --> day08/src/tree.rs:47:45
[INFO] [stdout]    |
[INFO] [stdout] 43 | /     fn rec_parse<'a, 'b, I>(iter: &'a mut I) -> Result<TreeNode, TreeParseError>
[INFO] [stdout] 44 | |         where I: Iterator<Item=&'b str>,
[INFO] [stdout] 45 | |               'b: 'a,
[INFO] [stdout] 46 | |     {
[INFO] [stdout] 47 | |         let child_count: usize = iter.next()?.parse()?;
[INFO] [stdout]    | |                                             ^ use `.ok_or(...)?` to provide an error compatible with `Result<TreeNode, TreeParseError>`
[INFO] [stdout] ...  |
[INFO] [stdout] 59 | |         })
[INFO] [stdout] 60 | |     }
[INFO] [stdout]    | |_____- this function returns a `Result`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `FromResidual<Option<Infallible>>` is not implemented for `Result<TreeNode, TreeParseError>`
[INFO] [stdout]    = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used on `Result`s, not `Option`s, in a method that returns `Result`
[INFO] [stdout]   --> day08/src/tree.rs:48:44
[INFO] [stdout]    |
[INFO] [stdout] 43 | /     fn rec_parse<'a, 'b, I>(iter: &'a mut I) -> Result<TreeNode, TreeParseError>
[INFO] [stdout] 44 | |         where I: Iterator<Item=&'b str>,
[INFO] [stdout] 45 | |               'b: 'a,
[INFO] [stdout] 46 | |     {
[INFO] [stdout] 47 | |         let child_count: usize = iter.next()?.parse()?;
[INFO] [stdout] 48 | |         let meta_count: usize = iter.next()?.parse()?;
[INFO] [stdout]    | |                                            ^ use `.ok_or(...)?` to provide an error compatible with `Result<TreeNode, TreeParseError>`
[INFO] [stdout] ...  |
[INFO] [stdout] 59 | |         })
[INFO] [stdout] 60 | |     }
[INFO] [stdout]    | |_____- this function returns a `Result`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `FromResidual<Option<Infallible>>` is not implemented for `Result<TreeNode, TreeParseError>`
[INFO] [stdout]    = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used on `Result`s, not `Option`s, in a method that returns `Result`
[INFO] [stdout]   --> day08/src/tree.rs:54:59
[INFO] [stdout]    |
[INFO] [stdout] 43 | /     fn rec_parse<'a, 'b, I>(iter: &'a mut I) -> Result<TreeNode, TreeParseError>
[INFO] [stdout] 44 | |         where I: Iterator<Item=&'b str>,
[INFO] [stdout] 45 | |               'b: 'a,
[INFO] [stdout] 46 | |     {
[INFO] [stdout] ...  |
[INFO] [stdout] 54 | |             .collect::<Option<Result<_, ParseIntError>>>()??;
[INFO] [stdout]    | |                                                           ^ use `.ok_or(...)?` to provide an error compatible with `Result<TreeNode, TreeParseError>`
[INFO] [stdout] ...  |
[INFO] [stdout] 59 | |         })
[INFO] [stdout] 60 | |     }
[INFO] [stdout]    | |_____- this function returns a `Result`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `FromResidual<Option<Infallible>>` is not implemented for `Result<TreeNode, TreeParseError>`
[INFO] [stdout]    = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 7 previous errors; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0277, E0432, E0554.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "886b5771e85995cffee150477b38d96ecffcf938d3098da67440d843ebdc0927", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "886b5771e85995cffee150477b38d96ecffcf938d3098da67440d843ebdc0927", kill_on_drop: false }`
[INFO] [stdout] 886b5771e85995cffee150477b38d96ecffcf938d3098da67440d843ebdc0927
