[INFO] cloning repository https://github.com/P79N6A/ocr_results_reader
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/P79N6A/ocr_results_reader" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FP79N6A%2Focr_results_reader", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FP79N6A%2Focr_results_reader'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 67c1d3e3f23f185ec08f5a3d61651fd062f36978
[INFO] testing P79N6A/ocr_results_reader against 1.47.0 for beta-1.48-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FP79N6A%2Focr_results_reader" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/P79N6A/ocr_results_reader on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/P79N6A/ocr_results_reader
[INFO] finished tweaking git repo https://github.com/P79N6A/ocr_results_reader
[INFO] tweaked toml for git repo https://github.com/P79N6A/ocr_results_reader written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/P79N6A/ocr_results_reader already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--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-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cd83bd9a4521b36c105fbd607698f7890f1197ca8f61da471194ce0481352fe9
[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" "cd83bd9a4521b36c105fbd607698f7890f1197ca8f61da471194ce0481352fe9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cd83bd9a4521b36c105fbd607698f7890f1197ca8f61da471194ce0481352fe9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cd83bd9a4521b36c105fbd607698f7890f1197ca8f61da471194ce0481352fe9", kill_on_drop: false }`
[INFO] [stdout] cd83bd9a4521b36c105fbd607698f7890f1197ca8f61da471194ce0481352fe9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "build" "--frozen" "--message-format=json", 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] 5bea8bf2266661432ca290e4a1df607d6adbbc623ef2f8d2d5f59f9813e370f3
[INFO] running `Command { std: "docker" "start" "-a" "5bea8bf2266661432ca290e4a1df607d6adbbc623ef2f8d2d5f59f9813e370f3", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling proc-macro2 v1.0.1
[INFO] [stderr]    Compiling syn v1.0.3
[INFO] [stderr]    Compiling serde v1.0.99
[INFO] [stderr]    Compiling regex-syntax v0.6.11
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling regex v1.2.1
[INFO] [stderr]    Compiling serde_derive v1.0.99
[INFO] [stderr]    Compiling serde_json v1.0.40
[INFO] [stderr]    Compiling all_results_reader_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]  --> src/main.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::collections::HashMap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Deserialize`, `Serialize`
[INFO] [stdout]   --> src/main.rs:11:13
[INFO] [stdout]    |
[INFO] [stdout] 11 | use serde::{Deserialize, Serialize};
[INFO] [stdout]    |             ^^^^^^^^^^^  ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Result`, `json`
[INFO] [stdout]   --> src/main.rs:12:18
[INFO] [stdout]    |
[INFO] [stdout] 12 | use serde_json::{json, Value, Result};
[INFO] [stdout]    |                  ^^^^         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `albumid` is assigned to, but never used
[INFO] [stdout]   --> src/main.rs:83:9
[INFO] [stdout]    |
[INFO] [stdout] 83 |     let mut albumid = "".to_owned();
[INFO] [stdout]    |         ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout]    = note: consider using `_albumid` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `tvid` is assigned to, but never used
[INFO] [stdout]   --> src/main.rs:84:9
[INFO] [stdout]    |
[INFO] [stdout] 84 |     let mut tvid = "".to_owned();
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_tvid` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:87:9
[INFO] [stdout]    |
[INFO] [stdout] 87 |     let mut f = BufWriter::new(f);
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `albumid` is never read
[INFO] [stdout]   --> src/main.rs:94:17
[INFO] [stdout]    |
[INFO] [stdout] 94 |                 albumid = caps[1].to_owned();
[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: value assigned to `tvid` is never read
[INFO] [stdout]   --> src/main.rs:95:17
[INFO] [stdout]    |
[INFO] [stdout] 95 |                 tvid = caps[2].to_owned();
[INFO] [stdout]    |                 ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ret`
[INFO] [stdout]    --> src/main.rs:100:13
[INFO] [stdout]     |
[INFO] [stdout] 100 |         let ret = read_json(&format!("{}/{}", json_file_dir, file_name));
[INFO] [stdout]     |             ^^^ help: if this is intentional, prefix it with an underscore: `_ret`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:87:9
[INFO] [stdout]    |
[INFO] [stdout] 87 |     let mut f = BufWriter::new(f);
[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] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 44.28s
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "5bea8bf2266661432ca290e4a1df607d6adbbc623ef2f8d2d5f59f9813e370f3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5bea8bf2266661432ca290e4a1df607d6adbbc623ef2f8d2d5f59f9813e370f3", kill_on_drop: false }`
[INFO] [stdout] 5bea8bf2266661432ca290e4a1df607d6adbbc623ef2f8d2d5f59f9813e370f3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e16c76bc67fc9b9411759c30a07a8d4696c90eafd730fed978fa7cbb1f2bb6cb
[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" "e16c76bc67fc9b9411759c30a07a8d4696c90eafd730fed978fa7cbb1f2bb6cb", kill_on_drop: false }`
[INFO] [stderr]    Compiling all_results_reader_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]  --> src/main.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::collections::HashMap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Deserialize`, `Serialize`
[INFO] [stdout]   --> src/main.rs:11:13
[INFO] [stdout]    |
[INFO] [stdout] 11 | use serde::{Deserialize, Serialize};
[INFO] [stdout]    |             ^^^^^^^^^^^  ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Result`, `json`
[INFO] [stdout]   --> src/main.rs:12:18
[INFO] [stdout]    |
[INFO] [stdout] 12 | use serde_json::{json, Value, Result};
[INFO] [stdout]    |                  ^^^^         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `albumid` is assigned to, but never used
[INFO] [stdout]   --> src/main.rs:83:9
[INFO] [stdout]    |
[INFO] [stdout] 83 |     let mut albumid = "".to_owned();
[INFO] [stdout]    |         ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout]    = note: consider using `_albumid` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `tvid` is assigned to, but never used
[INFO] [stdout]   --> src/main.rs:84:9
[INFO] [stdout]    |
[INFO] [stdout] 84 |     let mut tvid = "".to_owned();
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_tvid` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:87:9
[INFO] [stdout]    |
[INFO] [stdout] 87 |     let mut f = BufWriter::new(f);
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `albumid` is never read
[INFO] [stdout]   --> src/main.rs:94:17
[INFO] [stdout]    |
[INFO] [stdout] 94 |                 albumid = caps[1].to_owned();
[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: value assigned to `tvid` is never read
[INFO] [stdout]   --> src/main.rs:95:17
[INFO] [stdout]    |
[INFO] [stdout] 95 |                 tvid = caps[2].to_owned();
[INFO] [stdout]    |                 ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ret`
[INFO] [stdout]    --> src/main.rs:100:13
[INFO] [stdout]     |
[INFO] [stdout] 100 |         let ret = read_json(&format!("{}/{}", json_file_dir, file_name));
[INFO] [stdout]     |             ^^^ help: if this is intentional, prefix it with an underscore: `_ret`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:87:9
[INFO] [stdout]    |
[INFO] [stdout] 87 |     let mut f = BufWriter::new(f);
[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: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.62s
[INFO] running `Command { std: "docker" "inspect" "e16c76bc67fc9b9411759c30a07a8d4696c90eafd730fed978fa7cbb1f2bb6cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e16c76bc67fc9b9411759c30a07a8d4696c90eafd730fed978fa7cbb1f2bb6cb", kill_on_drop: false }`
[INFO] [stdout] e16c76bc67fc9b9411759c30a07a8d4696c90eafd730fed978fa7cbb1f2bb6cb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 1c7f0a5103667ee6dc95dec5a1e2a1d931e96e25bd8871f7100786ac6da2d42e
[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" "1c7f0a5103667ee6dc95dec5a1e2a1d931e96e25bd8871f7100786ac6da2d42e", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `std::collections::HashMap`
[INFO] [stderr]  --> src/main.rs:9:5
[INFO] [stderr]   |
[INFO] [stderr] 9 | use std::collections::HashMap;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Deserialize`, `Serialize`
[INFO] [stderr]   --> src/main.rs:11:13
[INFO] [stderr]    |
[INFO] [stderr] 11 | use serde::{Deserialize, Serialize};
[INFO] [stderr]    |             ^^^^^^^^^^^  ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Result`, `json`
[INFO] [stderr]   --> src/main.rs:12:18
[INFO] [stderr]    |
[INFO] [stderr] 12 | use serde_json::{json, Value, Result};
[INFO] [stderr]    |                  ^^^^         ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable `albumid` is assigned to, but never used
[INFO] [stderr]   --> src/main.rs:83:9
[INFO] [stderr]    |
[INFO] [stderr] 83 |     let mut albumid = "".to_owned();
[INFO] [stderr]    |         ^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr]    = note: consider using `_albumid` instead
[INFO] [stderr] 
[INFO] [stderr] warning: variable `tvid` is assigned to, but never used
[INFO] [stderr]   --> src/main.rs:84:9
[INFO] [stderr]    |
[INFO] [stderr] 84 |     let mut tvid = "".to_owned();
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: consider using `_tvid` instead
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `f`
[INFO] [stderr]   --> src/main.rs:87:9
[INFO] [stderr]    |
[INFO] [stderr] 87 |     let mut f = BufWriter::new(f);
[INFO] [stderr]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `albumid` is never read
[INFO] [stderr]   --> src/main.rs:94:17
[INFO] [stderr]    |
[INFO] [stderr] 94 |                 albumid = caps[1].to_owned();
[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: value assigned to `tvid` is never read
[INFO] [stderr]   --> src/main.rs:95:17
[INFO] [stderr]    |
[INFO] [stderr] 95 |                 tvid = caps[2].to_owned();
[INFO] [stderr]    |                 ^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `ret`
[INFO] [stderr]    --> src/main.rs:100:13
[INFO] [stderr]     |
[INFO] [stderr] 100 |         let ret = read_json(&format!("{}/{}", json_file_dir, file_name));
[INFO] [stderr]     |             ^^^ help: if this is intentional, prefix it with an underscore: `_ret`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:87:9
[INFO] [stderr]    |
[INFO] [stderr] 87 |     let mut f = BufWriter::new(f);
[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: 10 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.10s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/all_results_reader_rust-c6b6b6ed5d33875d
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "1c7f0a5103667ee6dc95dec5a1e2a1d931e96e25bd8871f7100786ac6da2d42e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c7f0a5103667ee6dc95dec5a1e2a1d931e96e25bd8871f7100786ac6da2d42e", kill_on_drop: false }`
[INFO] [stdout] 1c7f0a5103667ee6dc95dec5a1e2a1d931e96e25bd8871f7100786ac6da2d42e
