[INFO] cloning repository https://github.com/wismer/advent-2020
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/wismer/advent-2020" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwismer%2Fadvent-2020", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwismer%2Fadvent-2020'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9592c366609efaf34fb8f8effa4d76a3f2fa846f
[INFO] testing wismer/advent-2020 against master#99e3aef02079e9c10583638520cd0c134dc3a01d for pr-85530
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwismer%2Fadvent-2020" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/wismer/advent-2020 on toolchain 99e3aef02079e9c10583638520cd0c134dc3a01d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/wismer/advent-2020
[INFO] finished tweaking git repo https://github.com/wismer/advent-2020
[INFO] tweaked toml for git repo https://github.com/wismer/advent-2020 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/wismer/advent-2020 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 21d3f94777860a21de15baa68798561891ee6668dcd0878b81b6216ec1921ff7
[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" "21d3f94777860a21de15baa68798561891ee6668dcd0878b81b6216ec1921ff7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "21d3f94777860a21de15baa68798561891ee6668dcd0878b81b6216ec1921ff7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "21d3f94777860a21de15baa68798561891ee6668dcd0878b81b6216ec1921ff7", kill_on_drop: false }`
[INFO] [stdout] 21d3f94777860a21de15baa68798561891ee6668dcd0878b81b6216ec1921ff7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 527f2a48f424d8e0daad96c8319222207396f905d506989b393548d424c282c7
[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" "527f2a48f424d8e0daad96c8319222207396f905d506989b393548d424c282c7", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `id` is never read
[INFO] [stdout]   --> src/main.rs:96:13
[INFO] [stdout]    |
[INFO] [stdout] 96 |     let mut id = 0;
[INFO] [stdout]    |             ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_group`
[INFO] [stdout]    --> src/main.rs:127:13
[INFO] [stdout]     |
[INFO] [stdout] 127 |     let mut new_group = false;
[INFO] [stdout]     |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_group`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `number_of_answers`
[INFO] [stdout]    --> src/main.rs:157:9
[INFO] [stdout]     |
[INFO] [stdout] 157 |     let number_of_answers = answers.len();
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_number_of_answers`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:127:9
[INFO] [stdout]     |
[INFO] [stdout] 127 |     let mut new_group = false;
[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: function is never used: `parse_input_part_one`
[INFO] [stdout]   --> src/main.rs:17:4
[INFO] [stdout]    |
[INFO] [stdout] 17 | fn parse_input_part_one(numbers: &Vec<usize>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `parse_input_part_two`
[INFO] [stdout]   --> src/main.rs:40:4
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn parse_input_part_two(numbers: &Vec<usize>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `parse_day_five`
[INFO] [stdout]   --> src/main.rs:68:4
[INFO] [stdout]    |
[INFO] [stdout] 68 | fn parse_day_five() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `parse_seating`
[INFO] [stdout]   --> src/main.rs:91:4
[INFO] [stdout]    |
[INFO] [stdout] 91 | fn parse_seating(seating: Vec<char>) -> usize {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:71:5
[INFO] [stdout]    |
[INFO] [stdout] 71 |     file.read_to_string(&mut buffer);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:124:5
[INFO] [stdout]     |
[INFO] [stdout] 124 |     data.read_to_string(&mut buffer);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.02s
[INFO] running `Command { std: "docker" "inspect" "527f2a48f424d8e0daad96c8319222207396f905d506989b393548d424c282c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "527f2a48f424d8e0daad96c8319222207396f905d506989b393548d424c282c7", kill_on_drop: false }`
[INFO] [stdout] 527f2a48f424d8e0daad96c8319222207396f905d506989b393548d424c282c7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b98c3bd440e2b48d4c39545bbaa4f66a70dfa92730d2a206be8c08f8c6db4eea
[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" "b98c3bd440e2b48d4c39545bbaa4f66a70dfa92730d2a206be8c08f8c6db4eea", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `id` is never read
[INFO] [stdout]   --> src/main.rs:96:13
[INFO] [stdout]    |
[INFO] [stdout] 96 |     let mut id = 0;
[INFO] [stdout]    |             ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_group`
[INFO] [stdout]    --> src/main.rs:127:13
[INFO] [stdout]     |
[INFO] [stdout] 127 |     let mut new_group = false;
[INFO] [stdout]     |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_group`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `number_of_answers`
[INFO] [stdout]    --> src/main.rs:157:9
[INFO] [stdout]     |
[INFO] [stdout] 157 |     let number_of_answers = answers.len();
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_number_of_answers`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:127:9
[INFO] [stdout]     |
[INFO] [stdout] 127 |     let mut new_group = false;
[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: function is never used: `parse_input_part_one`
[INFO] [stdout]   --> src/main.rs:17:4
[INFO] [stdout]    |
[INFO] [stdout] 17 | fn parse_input_part_one(numbers: &Vec<usize>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `parse_input_part_two`
[INFO] [stdout]   --> src/main.rs:40:4
[INFO] [stdout]    |
[INFO] [stdout] 40 | fn parse_input_part_two(numbers: &Vec<usize>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `parse_day_five`
[INFO] [stdout]   --> src/main.rs:68:4
[INFO] [stdout]    |
[INFO] [stdout] 68 | fn parse_day_five() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `parse_seating`
[INFO] [stdout]   --> src/main.rs:91:4
[INFO] [stdout]    |
[INFO] [stdout] 91 | fn parse_seating(seating: Vec<char>) -> usize {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:71:5
[INFO] [stdout]    |
[INFO] [stdout] 71 |     file.read_to_string(&mut buffer);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:124:5
[INFO] [stdout]     |
[INFO] [stdout] 124 |     data.read_to_string(&mut buffer);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.77s
[INFO] running `Command { std: "docker" "inspect" "b98c3bd440e2b48d4c39545bbaa4f66a70dfa92730d2a206be8c08f8c6db4eea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b98c3bd440e2b48d4c39545bbaa4f66a70dfa92730d2a206be8c08f8c6db4eea", kill_on_drop: false }`
[INFO] [stdout] b98c3bd440e2b48d4c39545bbaa4f66a70dfa92730d2a206be8c08f8c6db4eea
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 3fa6134af172dacc84681a5454972fa68525edb42ed162757119985547aef2d1
[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" "3fa6134af172dacc84681a5454972fa68525edb42ed162757119985547aef2d1", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stdout] 
[INFO] [stderr] warning: value assigned to `id` is never read
[INFO] [stdout] running 0 tests
[INFO] [stderr]   --> src/main.rs:96:13
[INFO] [stdout] 
[INFO] [stderr]    |
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stderr] 96 |     let mut id = 0;
[INFO] [stdout] 
[INFO] [stderr]    |             ^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stderr]    = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `new_group`
[INFO] [stderr]    --> src/main.rs:127:13
[INFO] [stderr]     |
[INFO] [stderr] 127 |     let mut new_group = false;
[INFO] [stderr]     |             ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_group`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `number_of_answers`
[INFO] [stderr]    --> src/main.rs:157:9
[INFO] [stderr]     |
[INFO] [stderr] 157 |     let number_of_answers = answers.len();
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_number_of_answers`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:127:9
[INFO] [stderr]     |
[INFO] [stderr] 127 |     let mut new_group = false;
[INFO] [stderr]     |         ----^^^^^^^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `parse_input_part_one`
[INFO] [stderr]   --> src/main.rs:17:4
[INFO] [stderr]    |
[INFO] [stderr] 17 | fn parse_input_part_one(numbers: &Vec<usize>) {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `parse_input_part_two`
[INFO] [stderr]   --> src/main.rs:40:4
[INFO] [stderr]    |
[INFO] [stderr] 40 | fn parse_input_part_two(numbers: &Vec<usize>) {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `parse_day_five`
[INFO] [stderr]   --> src/main.rs:68:4
[INFO] [stderr]    |
[INFO] [stderr] 68 | fn parse_day_five() {
[INFO] [stderr]    |    ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `parse_seating`
[INFO] [stderr]   --> src/main.rs:91:4
[INFO] [stderr]    |
[INFO] [stderr] 91 | fn parse_seating(seating: Vec<char>) -> usize {
[INFO] [stderr]    |    ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/main.rs:71:5
[INFO] [stderr]    |
[INFO] [stderr] 71 |     file.read_to_string(&mut buffer);
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]    --> src/main.rs:124:5
[INFO] [stderr]     |
[INFO] [stderr] 124 |     data.read_to_string(&mut buffer);
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: 10 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.11s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/rust-b4a48de58eeb7d5c)
[INFO] running `Command { std: "docker" "inspect" "3fa6134af172dacc84681a5454972fa68525edb42ed162757119985547aef2d1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3fa6134af172dacc84681a5454972fa68525edb42ed162757119985547aef2d1", kill_on_drop: false }`
[INFO] [stdout] 3fa6134af172dacc84681a5454972fa68525edb42ed162757119985547aef2d1